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16-103325
A�kCITY OF Federal Way July 28, 2016 Marty Cannon 29437 10`' Avenue SW Federal Way, WA 98023 Email: t77artycannon@con7cast.net �� FILE, RE: File #16-103325-00-SH; GEOTECHNICAL CONSULTANT REVIEW Cannon Slope Stabilization, 29437 loth Avenue SW, Federal Way Dear Mr. Cannon: 33325 8th Avenue South Federal Way, WA 98003-6325 (253) 835-7000 www. cityoffederalway.. com Jim Ferrell, Mayor Amec Foster Wheeler (Amec), the City's geotechnical consultant, has reviewed your July 11, 2016, Geotechnical Report, prepared by Aspect Consulting, LLC, in addition to the Slope Soldier Pile Wall — Site Plan, dated July 2016, prepared by Aspect Consulting, LLC, for the development of the proposed soldier pile retaining wall. Amec's initial review has been completed. Enclosed please find the July 27, 2016, review comments from Amec. Based on the review of the submitted information and review of the Federal Way Revised Code (FWRC), Amec has identified specific issues and requirements that must be addressed prior to approval of the project. Please have Aspect Consulting revise the report to address the comments made by Amec. When resubmitting, please provide three copies of any revised plans or reports, accompanied by the enclosed Resubmittal Information form. I can be reached at 253-835-2641 or becky.chapin@cityoffederalway.com if you have any questions about this letter. Sincerely, Becky Chapin Associate Planner Mike Maisen, Aspect Consulting, LLC, mmaisen(c�t aspectconsulting.com enc: Resubmittal Information Form Amec Foster Wheeler Review Comments. dated July 27, 2016 Doc. I.D. 74277 ,As p e c t CONSULTING August 29, 2016 City of Federal Way 33325 8t' Avenue South Federal Way, Washington 98003 Re: Response to City and Geotechnical Consultant Review Comments Permit #16-103326-00-SF Cannon Slope Stabilization 29437 1Oth Ave SW Federal Way, Washington Aspect Consulting Project No. 150376 References: City Independent Plans Review Comments, Re: Permit # 16-103326-00-SF, prepared by City of Federal Way, dated July 18, 2016 Geotechnical Review of Documents, Re: File No. 16-103326-00-SF, prepared by Amec, Foster, Wheeler Environment and Infrastructure, Inc, dated July 27, 2016 Cannon Slope Stabilization — Soldier. Pile Wall — Plan Review Comments Federal Way Project #: 16103326SF, prepared by WC3, dated August 10, 2016 Canon Slope Soldier Pile Wall — Site Plan, Wall Sections, Erosion and Sedimentation Plan, prepared by Aspect Consulting, LLC, dated July 2016 Geotechnical Report Cannon Slope Protection, 2943710`l' Ave SW Federal Way, Washington 98023, prepared by Aspect Consulting, LLC, dated July 11, 2016 Dear Mr. Cole Elliott and Ms. Becky Chapin: Aspect Consulting, LLC (Aspect) has reviewed the referenced City of Federal Way, Amec Foster Wheeler, and WC3 review documents, and produced revisions to both the project plans and Aspect's Geotechnical Report. The revised plans along with this letter are submitted in response to correction notices. The revised plans meet the geotechnical criteria for slope protection, as outlined in the above -referenced reports. A summary of the changes made to the design and plans is provided below, with the reviewer's comment in italics followed by Aspect's response. City of Federal Way Comments Sheet G01 1. Please Clark the intent of General Note 12.2. The City cannot allow a project without a defined completion schedule. Marty and Katherine Cannon August 29, 2016 Project No. 150376 General Note 12.2 has been updated to reflect this requirement. 2. Due to the structural nature of the material behind the soldier pile wall, General Note 19.3 should be modified to state 90 or 95 percent compaction based on a Modified Proctor test. Backfill on the upslope side of the lagging should comprise pea gravel and be densified by rodding or probing. Rodded pea gravel is sufficient for the purposes of the design. A compaction requirement is not necessary for this instance in our professional opinion. General Note 19.3 has been updated on the plans to reflect this. Sheet C01 1. On the profile, please clarify why no lagging boards are indicated between Pile I and Pile 2. Lagging boards have been added to the profile on the plans. 2. On the plan, it is unclear why no lagging boards or piles are proposed for a return upslope along the eastern edge of the property while the western edge does show and upslope return. The soldier pile wall return on the western side of the proposed wall is designed to provide protection for a gap with the soldier pile wall on the neighboring property (29435 10`h Ave SW, Federal Way, Washington). The proposed soldier pile wall is designed to protected the yard. The lack of a return wall does not affect the performance of the design. Sheet CO3 1. Given the restrictive job site access, please clarify how the 40 feet long H-beams are to be conveyed to the site. Are segments to be welded together on -site? If so how will the protective coating be applied? We visited the Site with a pile contractor for a pre -permit -submittal site walk. The pile contractor plans to move the 40-feet-long H-beams from the staging area in the driveway to the eastern area marked "Lawn" on sheet CO using an excavator mounted drill. These H-piles will be moved whole and staged along the "Wood Wall" (Sheet CO1), then installed. 2. The geotechnical report discussed the use of jute matting for erosion control and site stabilization but the plan does not call out jute matting. Why? During the design phase of the project, we determined hydroseed was a more effective means of re -vegetating the slope. The geotechnical report has been updated to reflect this. Amec Foster Wheeler Review Comments 1. Please add a section to the report describing the landslide that occurred in February 2016 What are the most likely causes of the recent and future landslides? Page 2 Marty and Katherine Cannon August 29, 2016 Project No. 150376 The geotechnical report has been updated to describe the relevant landslide history. 2. What is the purpose of excavating in front of the soldier pile wall? Why is the excavation 4 feet? It seems like an excessive amount of earthwork within a landslide hazard. Please describe how disturbance to the steep slope will be prevented. We specify lagging to 6 feet below the top -of -pile to provide protection against two characteristic slide events. In the future, lagging may be installed an additional two feet below the bottom of the exposed wall (for a total wall height of 8 feet) as needed. Lagging installation will be accomplished by machine excavation stationed behind the wall and reaching over the wall to excavate a bench to a level of 4 feet below the top -of -pile. The additional 2 feet of excavation required for lagging will be accomplished with hand excavation, and this excavation will be backfilled resulting in a permanent bench with an elevation that is 4 feet below the top - of -pile. We specified the 4 feet deep bench to provide a working surface for wall construction, reduce the driving force on the weak soils in front of the wall and reduce slide hazards, and to provide access for future maintenance activities, if needed. Our experience on similar projects has been that excavation of the bench does not produce an unmanageable landslide hazard. We will add a note to the drawings indicating that large equipment shall not be operated on the bench and that the excavated material must be hauled offsite (as opposed to cast downslope, which will not be allowed). Suitable erosion control measures will be implemented for the temporary and permanent condition to protect against erosion. 3. The report needs to be clear and consistent about the recommended depth of the excavation (if needed) and the depth of lagging. The project overview section says lagging will go down 4 feet, but the lagging section says lagging will go down 6 feet, and then there is discussion about backfilling after placing lagging. The report language has been updated to clarify the reasoning for excavation and depth of lagging. 4. The discussion in the report regarding slide episodes, the number offeet of cantilever wall face that can be exposed, when tiebacks are needed, and the maximum exposed depth with tiebacks need to be provided in the design plan sheets also. The plans sheets should include a lateral earth pressure diagram, and a diagram and notes that explain when the wall needs additional support. The current design is not addressing possible future need for tie backs. This is a possible future benefit that does not need to be reflected in the design, but is documented in the report. A note will be added to the drawings stating that the maximum design height of the wall is 8 feet. Lateral pressures are provided in the report and do not need to be duplicated on the drawings. 5. Please provide more explanation for the seismic design. The earthquake magnitude (probability of exceedance) chosen for the wall design is a smaller earthquake than required by building codes, so the wall is not designed to withstand the same earthquake Page 3 Marty and Katherine Cannon August 29, 2016 Project No. 150376 forces as occupied structures. This should be explained thoroughly for the benefit of the current and future owners and the City. Failure of the wall would not impact the occupied structures; therefore, seismic design is not required. The building code (Section 15.6.1 of ASCE-7-10, which is incorporated to IBC by reference) does not require seismic design for walls if their failure will not impact an occupied structure or public gathering area. The seismic considerations incorporated into the design are voluntary and based on the owner's risk tolerance. 6. Please be consistent in the report, the slope stability analyses, and the structural calculations. In some places the design seismic force is noted as 0.24g and in others it is noted as 0.14g. The geotechnical report and appendices have been updated with a consistent pseudostatic coefficient (kh), based on a voluntary level of protection against a 108-year return period event. 7. Please provide Figure 2, Site Plan, at an engineering scale that shows the cross-section used for slope stability analyses. The report we received did not include Figures 1 and 2. We cannot comment why the figures were not included. Figures were provided with the submitted report to a conventional engineering scale. We trust that our revised report will be provided to AMEC in its entirety. 8. Please provide a geologic cross-section at engineering scale, or provide the slope stability figures at an engineering scale (same vertical and horizontal scale). There is no requirement to provide a geologic cross section, and the slope stability figures are provided to 1:1 scale. In our opinion, the provided figures present the information in a way that is understandable to a reviewer. 9. Slope stability analyses comments: a. Cohesion should not be used for long-term stability analyses offill, colluvium, or landslide deposits. Please provide analyses without cohesion for these soils. Cohesion is often used in professional practice with limit equilibrium slope stability analyses to model the effects of root reinforcement and capillary suction in near -surface sediments. In our opinion, this approach is within the standard of care for this type of analysis. b. It appears from the table in the slope stability analyses figures that groundwater was not included in the Pre -Fraser soils ("water surface = none'), but the boring logs show groundwater in these soils. Please revise the analyses to include groundwater in the Pre -Fraser soils. Slope stability analyses have been updated and the Pre -Fraser Nonglacial and Glaciolacustrine deposits as requested. The undifferentiated pre -Fraser sediments have been modeled to account for moist conditions observed in the bottom of boring 13-1 and a deeper piezometric surface inferred from nearby borings. Page 4 Marry and Katherine Cannon August 29, 2016 Project No. 150376 c. It does not appear that the slope stability analyses searched for the most critical slip surfaces because the slip surface exit point was restricted to an arbitrary point on the middle of the slope (about 10 feet below HA-1). Please provide analyses that allow the slip surface to exit anywhere on the slope, and most importantly, at the toe of the steep slope. This information should be provided to the current and future owner and the City. Once the most critical slip surfaces have been analyzed, then explain what slip surface (type of landslide) will be stabilized by the retaining wall. Slope stability analyses have been updated to allow surface to exit any point on the north -facing slope. d. The analysis doesn't seem to have included the zones of disturbed soils noted in the boring logs. Please comment on the disturbed zones and how or if they should be analyzed. The presence of the disturbed zones was factored into the engineering properties of the soil units in which they were observed. 10. Were the same soil properties and slope cross-section used to calculate the lateral earth pressures for the retaining wall design? How was the steep slope below the wall factored into the passive pressure value? The same soil properties were used to calculate lateral earth pressures. We accounted for the steep slope by applying a correction factor to the equation for determining the passive coefficient (Kp) per NAVFAC 7.2-64 of R = -30. 11. The design plans should include a re -vegetation plan of disturbed areas after construction. Hydroseed is specified for permanent restoration. 12. An as -built survey of the retaining wall should be required since this will provide baseline data for monitoring any long-term movement of the wall. The report has been modified to include a recommendation for installing selected measuring points, which would be monitored on a periodic basis as necessary. This can be accomplished after the completion of the wall. WC3 Comments S1. Section 3. S.1 of the geotechnical report outlines special inspections that will be required during the installation of the wall. Please complete the attached City of Federal Way "Special Inspection Agreement" and submit for review. Please see attached City of Federal Way "Special Inspection Agreement". S2. Please clam the treatment of the timber lagging as required by IBC 2303.1.9. The plans should also note the requirement for lagging to be labeled per IBC 2303.1.9.1. The plans have been updated to include this requirement. Page 5 Marty and Katherine Cannon August 29, 2016 Project No. 150376 S3. Comment #5 in the letter from AMEC Foster Wheeler notes that the seismic design parameters do not meet the requirements of the building code. Page 6 of the geotechnical report states that the design considers a seismic event having a 50%probability in 75 years. Please confirm that the lateral seismic component (kh=0.07) that is used in the design is at least equivalent to 0.7 times the nominal earthquake loads specified in the building code as required by IBC 1807.2.3. Failure of the wall would not impact the occupied structures; therefore, seismic design is not required. The building codes do not require seismic design for walls if their failure will not impact an occupied structure or public gathering area. The seismic considerations incorporated into the design are voluntary and based on the owner's risk tolerance. S4. Please clarify if the comments made by "EC Foster Wheeler have been addressed at this time. See above. Limitations Work for this project was performed for the Marty and Katherine Cannon (Client), and this letter was prepared in accordance with generally accepted professional practices for the nature and conditions of work completed in the same or similar localities, at the time the work was performed. This letter does not represent a legal opinion. No other warranty, expressed or implied, is made. All reports prepared by Aspect Consulting for the Client apply only to the services described in the Agreement(s) with the Client. Any use or reuse by any party other than the Client is at the sole risk of that party, and without liability to Aspect Consulting. Aspect Consulting's original files/reports shall govern in the event of any dispute regarding the content of electronic documents furnished to others. Sincerely, Aspect consulting, LLC Henry Haselton, PE Principal Geotechnical Engineer haselton@aspectconsulting.com Attachments City of Federal Way Special Inspection & Testing Agreement Form WA—GEOTECH\150376 Cannon Residence Slope Recon\Deliverables\Geotech Report\Comment Response Letter\20160629- Desig nReviewComments-Response.docx Page 6 Building Division CITY OF 33325 81h Ave. S. Federal WaySPECIAL INSPECTION & Federal Way, WA 98003 Phone: (253) 835-2633 TESTING AGREEMENT Fax: (253)835-2609 (All references are per the 2012 International Building Code) Project Name: _Cannon Slope Protection Project Address: 29437 loth Ave SW Federal Way, Washington Building Permit Number: Date Issued: _ BEFORE A PERMIT CAN BE ISSUED: The registered design professional in responsible charge shall fill out the Agreement and include the name of each inspector as well as their appropriate license/certification number. Two (2) copies of this form are to be submitted to the City prior to the issuance of a building permit. If changes are made as to who will perform the special inspections a new form shall be submitted and turned into the Building Permits & Inspections Division for approval. STATEMENT OF SPECIAL INSPECTIONS: In addition to this Agreement, a "Statement of Special Inspections" shall be provided per IBC 1704.3. This Statement shall be made as part of the approved plans, and be placed in a conspicuous location, such as the first page of the construction plans or the first page of the structural sheets. SPECIAL INSPECTORS: All special inspectors shall be approved by the Building Department prior to performing any duties. The special inspector shall provide proof of certification as a special inspector for each inspection item. SPECIAL INPSECTION REPORTS: Special inspection reports are to meet the requirements of IBC 1704.2.4. Copies of each report are to be sent to the address listed in the letterhead noting the Project Address and Permit Number. A final report shall be submitted stating that all special inspection and structural testing items were completed and are in conformance with the approved design drawings and specifications. Items not in conformance, unresolved items, or any discrepancies in inspection coverage (i.e. missing inspections, periodic inspections when continuous was required, etc.) shall be specifically itemized in the final report. GENERAL SPECIAL INSPECTION ITEMS (per IBC Chapter 17) (Only checked kerns are required) Areas requiring special inspection: Name of Agency: Name of Inspector: License/Cert. No. ❑ Unapproved Fabricators (IBC 1704.2.5) Other than Structural Steel (IBC Table 1705.2.2) ❑ Steel floor & roof decks ❑ Welding of reinforcement ❑ Cold -formed steel Structural Steel ❑ Welding (Per N5.4 of AISC 360-10) ❑ Details (Per N5.7 of AISC 360-10) ❑ High -strength bolts (Per N5.6 of AISC 360-10) Concrete Construction (per IBC Table 1705.3) ❑ Reinforcement, embeds, anchors ❑ Formwork ❑ Materials ❑ Shotcrete ❑ Post-tensioned/Pre-stressed Concrete ❑ Erection of precast concrete URL: www.cityoffederalway.com Page 1 of 3 CITY OF Federal Way SPECIAL INSPECTION & TESTING AGREEMENT Building Division 33325 81h Ave. S. Federal Way, WA 98003 Phone: (253) 835-2633 Fax: (253) 835-2609 GENERAL SPECIAL INSPECTION ITEMS (per IBC Chapter 17) - continued [Only checked items are required] Areas requiring special inspection: Name of Agency: Name of Inspector: License/Cert. No. Masonry Construction (IBC 1705.4) ❑ Prior to Construction (Article 1.15, TMS-602) ❑ As Construction Begins (Article 1.19.2, TMS-402) ❑ Prior to Grouting (Table 1.19.2, TMS-402) ❑ During Construction (Per TMS-402 & TMS-602) Wood Construction ❑ High -Load Diaphragms (IBC 1705.5.1) ❑ Wood Trusses > 60ft (IBC 1705.5.2) 7 Soils (IBC Table 1705.6) Aspect Consulting Jesse Favia LG# 3111 ❑ Driven Deep Foundations (IBC Table 1705.7) ❑ Cast -in -place Deep Foundations (IBC Table 1705.8) ❑ Helical Pile Foundations (IBC 1705.9) ❑ Sprayed Fire -Resistant Materials (IBC 1705.13) ❑ Mastic & Intumescent Coatings (IBC 1705.14) ❑ EIFS (IBC 1705.15) ❑ Fire -Resistant Penetrations (IBC 1705.16) ❑ Smoke Control (IBC 1705.17) R Other Soldier Pile Wall (IBC 1705.1.1) Aspect Consulting Jesse Favia LG# 3111 ❑ Other (IBC 1705.1.1) SPECIAL INSPECTIONS FOR SEISMIC RESISTANCE (IBC Section 1705.11) [Only checked items are required] Areas requiring special inspection: Name of Agency: Name of Inspector: License/Cert. No. ❑ Structural Steel (IBC 1705.11.1 & AISC 341-10) ❑ Structural Wood (IBC 1705.11.2) ❑ Cold -formed Steel (IBC 1705.11.3) ❑ Mechanical & Electrical Components (1705.11.4) ❑ Architectural Components (IBC 1705.11.5) ❑ Storage Racks (IBC 1705.11.7) URL: www.cityoffederalway.com Page 2 of 3 Building Division CITY OF 33325 81h Ave. S. Federal Way SPECIAL INSPECTION & Federal Way, WA 98003 Phone: (253) 835-2633 TESTING AGREEMENT Fax: (253)835-2609 Declaration by Architect/Engineer I, the design professional in responsible charge for this project, declare that the above listed special inspection and structural testing items are required for this project in accordance with IBC Chapter 17. Signature Date Declaration by Owner I, the Owner of the project, declare that the above listed firm(s) or individual(s) are hired by me to perform special inspections and structural testing for the project pursuant to IBC 1704.2. Signature Date CONTRACTOR RESPONSIBILITY: Each contractor involved with the construction of wind or seismic force -resisting systems shall comply with the requirements of IBC 1704.4. The contractor is responsible for providing the special inspector access to approved plans and contract documents at the job site. All special inspection records shall be retained at the job site by the contractor and shall be made available to the Building Department upon request. Declaration by General Contractor I, the General Contractor of the project, agree to comply with the "Contractor Responsibility" items noted above. Signature Date URL: www.cityoffederalway.com Page 3 of 3 CITY OF � Federal Way July 15, 2016 Marty and Katherine Cannon 29437 10"' Avenue SW Federal Way, WA 98023 n7artyCannon@con7cast. net RE: File #16-103326-00-SH; CONSULTANT REVIEW ESTIMATE Cannon Slope Stabilization, 29437 loth Avenue SW, Federal Way Dear Mr. and Mrs. Cannon: 33325 8th Avenue South Federal Way, WA 98003-6325 (253) 835-7600 www, cityoffederalway.. com Jim Ferrell, Mayor Please find the enclosed Geotechnical Consultant Task Authorization form provided by the City and Amec Foster Wheeler (Amec) for review of the submitted Geotechnical Report and Soldier Pile Wall plans, prepared by Aspect Consulting, LLC. The normal course of action for the City is to set up an account to be funded by the applicant and drawn down by the work performed by Amec. Please note: any funds that are not used will be returned to you. At this point, please review the proposed work description. If you agree with the cost estimate, payment in the amount of $2,500.00 (check must be payable to the City of Federal Way) and your signature on the City's `Geotechnical Consultant Authorization Form' must be submitted before the review will commence. Following receipt, I will authorize Amec to begin their formal review. If you have any questions regarding this letter or your project, please contact me at 253-835-2641 or Becky.chapin@cityoffederalway.com. Sincerely, Becky Ch in Associate Planner enc: Geotechnical Consultant Authorization Form City of Federal Way Invoice c: Mike Maisen_ Aspect Consulting, mmaisen@aspectconsulting.com Doc I D. 74127 GEOTECHNICAL CONSULTANT AUTHORIZATION FORM Date: July 14, 2016 City: City of Federal Way Community Development Department 33325 8th Avenue South Federal Way, WA 98003 Consultant: Todd Wentworth, Geotechnical Engineer Amec Foster Wheeler 11810 North Creek Parkway North Bothell, WA 98011 todd.wentworth@amecfw.com 425-368-0937 Project: Cannon Slope Stabilization 29437 101h Avenue SW Parcel #119600-2265 File No.: 16-103325-00-SH (Shoreline Substantial Development Exemption Permit) Project Proponent: Marty and Katherine Cannon 29437 10`h Avenue SW Federal Way, WA 98023 (253)376-0072 Project Proponent Aspect Consulting, LLC Geotechnical 401 2nd Avenue South, Suite 201 Consultant: Seattle, WA 98104 206-328-7443 Project Planner: Becky Chapin, Associate Planner beck .cha in@cit offederalwa .com 253-835-2641 Project Background: According to the city's critical areas map, the property contains erosion and Iandslide hazard areas. A portion of the proposed project is located within the "Urban Conservancy" shoreline designation while the majority is outside the shoreline jurisdiction. As such, two different critical area codes apply to the project as noted below. The applicant has submitted a geotechnical report and design plans for a proposed soldier pile wall. The property is located along the top of a steep slope above the Puget Sound where shallow landslides have occurred. The report addresses stabilization alternatives and geotechnical design recommendations for the selected alternatives. Engineered plans have also been included. Documents • Geotechnical Report, Cannon Slope Protection (dated July 11, 2016) Provided: prepared by Aspect Consulting, LLC. • Cannon Slope Soldier Pile Wall — Site Plan, Wall Sections, Erosion and Sedimentation Plan (dated July 2016) prepared by Aspect Consulting. Task Scope: ■ Review submitted documents for conformance to Federal Way Revised Code (FWRC). ■ Within the shoreline jurisdiction, all work on or within 25 feet of these areas is regulated under Federal Way Revised Code (FWRC) 15.05.040(4)(b) and 15.10.160. ■ Outside the shoreline jurisdiction, all work on or within 50 feet of these areas is regulated under FWRC 19.145.130 and 19.145.220-250. ■ Provide a memorandum identifying additional information requested as necessary. ■ Conduct site visit as necessary. ■ Provide written response as to whether or not Amec Foster Wheeler concurs with Aspect Consulting's recommended actions. Task Cost: Not to exceed $ S without a prior written amendment to this Task Authorization. Acceptance: City of Fed al Way rl y COnsultanL -_Ames Foster Wheeler Project ProponeEt Date Date Geotechnical Consultant Authorization Form 2 COMMUMTY & Eck. lout DEVELOPMENT DEPARTMENT - � 1 33325 8* Avenue South RECEIVED Federal Way, WA 98003-6325 uTr of 253-835-2601; Fax 253-835-2809 Federal Way JUL 112016 www.ciiyoffcMlway ccom C:M OF FEDERAL WAY SHORELINE SUBSTAMIAL DEVELOPMENT PERMIT EXEMPTION APPLICATION Foe # iC? TO BE COMPLETED BY APPLICANT Project Name: Cannon Residence Slope Stabilization Project Address: 29437 loth Ave SW, Federal Way, WA, 98023 Applicant: M and Katherine Cannon Mailing Address: same as above Phone Number: 253-376-0072 E-mail: martycant3on@comcast net Description of Project: Construct a cantilevered soldier pile wallnear the to of the slo in order to protect the upland residence and yard from future shallow colluvial landslides. The wall will, consist of 40-foot Iles s armed by timber 1 m . All construction will be at least 1 g0 feet away from ordinary high water Meets the criteria for exemption under which section of * WAC 173-27-040: (2)(g) *Washinzlon Adr.pinistrative Code online: aaa s.leg.wa.gov Signature '7 • -2 Date Bulletin #143 — March 25, 2013 1 of 2 kAHandout0horeline Exemption TO BE COMPLETED BY STAFF 1) The proposed development is consistent with Section Z of WAC 173-27-040 and is therefore exempt from the Substantial Development Permit Process. f Yes ❑ No (explanatory narrative attached) 2) Proposal requires: Yes No ❑ K Shoreline Variance ❑ A Shoreline Conditional Use ❑ Q Review, Approval or Permit by other State or Federal Agency 3) Proposal complies with applicable provisions of the City's Shoreline Master Program. J ' )'Cs ❑ No Condition(s) attached: Yes ❑ No 4) In accordance with FWRC Section 15.05.130, this application is hereby: X Approved ❑ Denied Director, Com Mty Development Department Date Distribution: ZL Applicant - V k ez �w�ni J4 Owner W File ❑ Outside Agency Bulletin #143 — March 25, 2013 2 of 2 k:\Handouts\Shoreline Exemption 40kCITY OF 101'::tSP Federal Way Conditions of Shoreline Exemption Approval Federal Way Revised Code (FWRC) 15.05.130 `Shoreline Exemption' Cannon Slope Stabilization, File #16-103325-00-SH The Planning Division has reviewed the shoreline substantial development permit exemption based on the exemption provision from WAC 173-27-040(2)(g), relevant code sections of FWRC Chapter 15.05 Shoreline Management, materials submitted July 11, 2016, and subsequent resubmittals received August 31, 2016. PROPOSAL The applicant has proposed to construct a cantilevered soldier pile wall near the top slope to protect the upland residence and yard from future shallow landslides. The property is located at 29437 10"' Avenue SW. The proposed retaining wall will include steel h-beams that are 40 feet long. The exposed portion of the wall, 4 feet, will include timber lagging spanning between the h-beams. Over time the shallow landslides will continue to occur downslope of the wall increasing the exposed height of the wall, with a maximum exposed height of 8 feet. The wall can be retrofitted in the future according to the volume of mass wasting that occurs below the wall in response to the continued coastal erosion process. CODE ANALYSIS ■ Shoreline Management A portion of the property is designated `Urban Conservancy' in the city's Shoreline Management Plan (SMP) overlay. Areas within 200 feet of the marine shoreline, including the Urban Conservancy designation area, are regulated under the state's Shoreline Management Act, which is administered locally via the city's SMP. The project is exempt from Shoreline Substantial Development permit provisions pursuant to WAC 173-27-040(2)(g), construction on shorelands by an owner of a single-family residence and those structures and developments that are normal appurtenances. Critical Areas The subject property is also located within a Geologically Hazardous Area (GHA), erosion, steep slope, and landslide hazard area. Any actions proposed to repair the damaged hillside are subject to shoreline standards and critical areas standards pursuant to FWRC 15.10.160, and may be approved by the director only if no reasonable alternative exists and if the proposal will not lead to or create any increased slide, seismic, or erosion hazard. The applicant submitted a Geotechnical Report, prepared by Aspect Consulting, dated July 11, 2016, for the proposed cantilevered soldier pile wall along the top of the slope. The City's geotechnical consultant Amec Foster Wheeler (Amec) provided third party review of the report. Aspect submitted a revised report on August 31, 2016. Based on the resubmitted report Amec is satisfied that all comments have been adequately addressed and the geotechnical documents appear to conform to FWRC Chapter 15.10, Critical Areas. Amec concurs with the recommendations as proposed in the Aspect Geotechnical Report and Soldier Pile Wall design plans. The proposed cantilevered wall will not stop mass wasting delivery to the beach and beach nourishment typical of feeder bluffs. The nearshore process should not be affected by the proposed wall and the project will not directly impact shoreline processes. As proposed, any temporary disturbance of the soil and vegetation will be self-contained within the site and re -vegetated following construction. ■ Retaining Walls Based on FWRC 19.120.120, Rockeries and retaining walls, for single-family residential lots, retaining walls must be 1) a maximum of six feet in height as measured from finished grade at base of wall to top of wall; 2) composed of brick, rockery, textured or patterned concrete, or other masonry product. Other materials may be used with approval of the community development director. A modification to composition of the wall, pursuant to FWRC 19.120.050, is approved. Wood lagging is proposed for the retaining wall structure and is allowed as an alternative to the required masonry product. As constructed, the visible portion of the wall is four feet. There is potential that additional timber lagging will be required if additional landslide activities occurs. CONDITIONS OF APPROVAL 1. In the event that any ground -disturbing activities or other project activities related to this development uncovers protected cultural material (e.g., bones, shell, antler, horn, or stone tools) an Inadvertent Archaeological and Historic Resources Discovery Plan must be implemented as provided by Gretchen Kaehler, DAHP. 2. Aspect Consulting must be on site during construction to monitor slope stability conditions and confirm construction activities do not adversely affect site stability. 3. A letter, prepared by Aspect Consulting, verifying construction of the wall is in compliance with recommendations of the geotechnical report must be submitted to the City no later than 30 days after the walls have been finalled. 4. An as -built survey of the retaining wall is required after the wall is constructed. This will provide baseline data for monitoring any long-term movement of the wall. 5. At the time that additional timber lagging is required, contact the Planning Department to inform them of the construction work that is to occur and to obtain permit approval. Prepared by: Becky Chapin, Associate Planner Date: September 28, 2016 Cannon Slope Stabilization, File #16-103325-00-SH/Doi. i.D. 74761 Conditions of Shoreline Exemption Approval Page 2 6 GENERAL NOTES 1. ALL WORKMANSHIP AND MATERIALS SHALL CONFORM TO THE MOST CURRENT STANDARD BUILDING CODES AS ADOPTED BY THE CITY OF DES MOINES. 2 THE CONTRACTOR IS RESPONSIBLE FOR THE MEANS AND METHODS OF CONSTRUCTION, THE COORDINATION OF ALL WQRK, SAFETY OF ALL PERSONS AT THE PROJECT SITE, AND SHALL COMPLY WITH ALL JOB RELATED SAFETY STANDARDS. THE CONTRACTOR IS RESPONSIBLE FOR DETERMINING ACTUAL CONDITIONS OF ALL EXISTING UTIUTIES SHOWN ON THE PLANS AND THO6B UrMITIES ANO UNDERGROUND OBSTRUGTIONS NOT SHOWN ONTHE PLANS, THE CONTRACTOR SHALL REI.IOVE ALL ABANDONED UTILITIES OR U NOERGROUND OBSTRUCTIONS THAT INTERFERE WITH NEW CONSTRUCTION• EXCAVATIOU SLOPES SHALL BE SAFE AND NOT GREATER THAN THE LIMITS SPECIFIED BY. LOCAL, STATE AND NATIONAL SAFETY REGULATIONS. 3. THE CONTRACTOR SHALL PROVIDE PROTECTION FOR PEDESTRIANS AND VEHICULAR TRAFFIC WHEN CONSTRUCTION ACTIVITIES WARRANT SUCH PROTECTION. 4 A COPY OF THESE APPROVED PLANS AND ANY REQUIRED PERMITS MUST BE ON SITE AT ALL TIMES. 5. THE REQUIREMENTS OF THIS PLAN AR THE, MINIMUM REQUIREMENTS 07£Y DO NOT REPLACE, REPE AL. ABROGATE, SUPERSEDE, OR AFFECT ANY OTHER MORE STRINGENT REQUIREMENTS, RVLES, REGULATIONS, SIANCARDS OR RESTRICTIONS. 6. ALL SURVEYING ANDSTAKING OF IMPROVEMENTS IS TO BE PROVIDED BYTHE CONTRACTOR. CONTRACTOR S14A64 FIELD VERIFY SITE CORORTONS PRIOR TO STARTINGANDSHALL NOTIFY ENGINEER IF THERE ARE DISCREPANCIES WITH THE PLANS. 7. CONTRACTOR SHALL PROTECT NEARBY EXISTING UTILITIES, STRUCTURES, PAVEMENTS AND FACILITIES. B CONTRACTOR SHALL PROTECT ANY POWER POLES NEAR EXCAVATION PER WAC 296-155-655(9)(4 9. THE CONTRACTOR SHALL KEEP AFFECTED OFFSITE STREETS CLEAN ATALLTIMES. 10 THE ENGINEER MUST BE ONSITE DURING CRITICAL CONSTRUCTION OPERATIONS. 11. REFERENCE DATA THE EXISTING SITE, TOPOGRAPHIC, UTILITY OATH, AND THE PROPOSED GRADES AND ELEVATIONS ARE BASED ON THE FOLLOWING ELECTRONIC DRAWINGS: PACE SURVEY 01119=16 ALL ELEVATIONS REFERENCE NAVO 88 12. THE SCOPE OF WORK TO BE PERFORMED INCLUDES THE FOLLOWING: 12.1. REMOVAL OF TREES, FENCE, STATUE, AND LANDSCAPING DURING CONSTRUCTION, 1 122. CON OF 60-FT LEVERED SOLDIER PILE WAIL VOTH TREATEOTIMBER LAGGING AND AMAXU.IIM DESIGN HEiCmT OF FEET TO ADC MNI FOR I'D(ENTIAt F'41T URE *LICE EVENTS AS SHOWN ON THE PLANS, 12.3. RESTORATION OF SURFACING ("MALT, CEMENT, SLOPE VWUATK" TO EXISTING COHDITIONS (ORBETTER) UNLESS OTHERWISE SPECIFIED BELOW IN NOTE 20. �� 13. GEOTECHNICAL INFORMATION IS PROVIDED BY ASPECT CONSULTING, L ,DATED INCUBI 20f9. C(rYTRACTQR IS RESPONSIBLE FOR REVIEWING ALL INFORMATION, AND COMPLYING WITH BTE�CF)N LK. J4ENDA'TIONS PROVIDED IN THE REPORT. 14. THE CONIRACI OR SHALLEMPLOY THE FOLLOWING BEST A9LNAGE>IENT PRACTICES IOMP-S) TO REDUCE THE P017ENTIAL FOR EROSION OF EXPOSED SOIL AND TO LIMIT SEOIMEJLT GENERATION. SEE SHEET CO3 FOR EROSION AND SEDIMENTATION CONTROL DETAILS. 14.1. COVERALL SPOILS AND SOIL STOCKPILES DURING WET WEATHER AS MUCH AS POSSIBLE 14.2. PROVIDE ACCESS CONTROLS. 14.3. CLEANUP ANY SOILS DEPOSITED ON THE SURROUNDING STREETS AT THE END OF EACH DAY 16 MATERIALS 15l. DRILLED SHAFTS SHALL BE BACKFILLED USING LEAN MIX CONCRETE OR CONTROLLED DENSITY FILL (COF) WITH A 28-DAY COMPRESSIVE STRENGTH OF APPROXIMATELY 1,000 PSI. 15.2. STRUCTURAL STEEL SECTIONS SHALL CONFORM TO ASTM A992 GRADE 50. THE UPPERMOST 10-FEET OF THE STEEL SECTIONS SHALL BE PROTECTED FROM CORROSION WITH A 16 MIL EPDXY TOPCOAT. r 15.4. TIMBER LAGGING SHALL BE NEW TREATED DOUGLAS-FIR-LARCH, GRADE NO. W. OR BETTER AND SHALLBE 4-INCHES THICK (NOMINAL), AND AT LEAST 6-INCHES WIDE. NEW CUTS SHALL BE PRESERVATIVE TREATED iN ACCORDANCE W AWPA U1 REQUIRE EATS vsE LATE RY UGRB AH TO A rhiiMU RETENTIA4 0 4 LSSACF. `�f 15.5. SOLDIER PILE WALL BACKFILL SHALL CONSIST OF A MINIMUM OF 4-INCHES (AND MAXILIUMOF I2-INCHES)OF GRAVEL BACKFILL FOR WALLS, AS DEFINED IN SECTION "312(2) OF THE 2014 WSODT STANDARD SPECIFICATIONS FOR ROAD, BRIDGE, AND MUNICIPAL CONSTRUCTION. 16. PROTECT EXISTING CATCH BASIN AND DRAINAGE PIPE ON EAST SIDE OF PROPERTY. 17. TWO (2) WEEKS PRIOR TO WORK COMMENCING, THE CONTRACTOR SHALL PROVIDE MANUFACTURER'S DOCUMENTATION AND OR SAMPLES OF THE MATERIALS PLANNED FOR USE W THE CONSTRUCTION AND SUBMIT A WORK PLAN DETAILING EQUIPMENT, METHODOLOGY, STAGING REQUIREMENTS, AND OTHER LOGISTICAL PLANS. 17.1. CONTRACTOR SHALL ATTEND A PRE -CONSTRUCTION CONFERENCE WITH THE ENGINEER AND PERMITTING AGENCY. Cannon Slope Soldier Pile Wall 29437 10th Ave SW Federal Way, WA 18 DRILLED SHAFT CONSTRUCTION 18.1. THE SOLDIER PILE SHAFTS SHALL BE MINIMUM OF241NCHES IN DIAMETER (NOMINAL}, ANDMUST BE DRILLED AT LEAST ONE FOOT DEEPER TRkN THE BOITOM OF STEEL SOLDIER PILES INDICATED IN THE MANS. 182. THE CUNT-aACTOR SHALL PROVIDE BU ITABLE EQUIPMENT TO ADVANCE THE SHAFT EXCAVAT!ON'RO THE DESIGN DEPTH IN A CONTINUOUS OPERATION. IT iS THE CONTRACTOR'S RESPONSIBILITY TO ENSURE 7HE SAFETYOF THE SHAFT-, SURROUNDING SOIL, AND THE STABILITY OF THE SHAFT SIDE WALLS, IF CAVING CONDITIONS ARE ENCOUNTFOIED. THE CONTRACTOR SHALL USE YEMPOPIARY CASINO OR OTHER METHODS, ON APPROVAL OF THE ENGINEER. NO EXTRA PAYMENT WILL DE MADE FOR USE OF TEMPORARY CASING OR OTHER SHAFT STABL-iZA71DN METHODS. 1B.3. SHAFT EXCAVATRON MAY BE SUSPENDED WITH THE APPROVAL OF THE ENGINEER. IN SUCH A CASE, THE SHAFT SHALLSE SECURED VRTH AN APPROPRIATE SAFETY COVER. IF NECESSARY, A TEMPORARY CASING SHALL BE USED. 18.4. THE CONTRACTOR SHALL USE A CLEANOUTWOKETARWHER MEANS APPROVED BY THE ENGINEER, TO CLEAN THE BOTTOM OF THE SHAFT SUCH THAT NEGLIGIBLE LOOSE OR DISTURBED MATERIAL REMAINS ON THE EXCAVATION BASE. 18.5. ALL *WAFT EXCAVATION* MUST Be INSPECTED BY TS3 ENGINEER. THE CONTRACTOR SHALL NOTIFY THE ENGINEER AT LEAST 72 BUSINESS HOURS PRIOR TOTNE DRILLING OF SOLDIER PIES OR OTHER WORK ON SITE. IMMEDIATELY UPON COMPLETION OF SHAFT EXCAVATION. THE CONTRACTOR SHALL NOTIFY THE ENGINEER THAT THE SHAFT EXCAVATION IS READY FOR INSPECTION. THE CONTRACTOR SHALL HAVE AVAIABLE A SLITABL E LIGHYFOR. WSpgCCH[X10F IHE 6HAF 1 EXCAYAl ION, AMU PLUMB WEXikRT AND TAPE TO CHECK VE RTItQ ALIGNMENT AND DEPTH. 18.0. DEVIATION OF SHAFT EXCAVATIONS FROM THE DESIGH LOCATIONS SHALL NOT EXCM THREE(3) INCHES. ALL EXCAVATIONS NOT WITHIN TOLERANCE SHALL BE CORRECTED OR REPLACED AT THE CONTRACTOR'S EXPENSE 18.7. DEVIATION OF SOLDIER PILES FROM VERTICAL (PLUMB) SHALL NOT EXCEED }INCH PER 10 VERTICAL FEET OF SHAFT. 188. LEAN MIX CONCRETE SHALL BE PLACED NOTHOVTDELAY FOLLOWING ACCEPTANCE BY THE ENGINEER. LEAN MIX CONCRETE CAST CONTINUOUSLY IN A SINGLE POUR AND SHALL BE PLACED BY TREMIE METHODS IF THERE IS MORE THAN 12 INCHES OF WATER IN THE SHAFT. I&G. NO TWO CONSECUTIVE PILES MAY BE DRILLED OR INSTALLED ON THE SAME DAY. THE WALL MAY NOT BE LOADED UNTIL AT LEAST 12 HOURS AFTER PLACLNO THE LEAN MCC CONCRETE IN THE SHAFTS 18.10. DRILLED SHAFT SPOILS SHALL BE EXPORTED FROM THE SITE TO A SUITABLE DISPOSAL AREA. 19 LAGGING, BACKFILL, AND ON -SITE SOIL REUSE 19.1. LAGGING SHALL BE INSTALLED IN ACCORDANCE WITH ELEVATIONS AND OTHER SPECIFICATIONSAS DETAILED ON PLANS. FOR DRAINAGE PURPOSES, LAGGING BOARDS WILL BE INSTALLED WITH A MINIMUM GAP OF J. INCH BETWEEN BOARDS LAGGING BOARDS WILL 13E INSTALLED LEVEL WITHIN A1INCH VERTICAL TOLERANCE PER &FOOT SPAN OF r192. LAGGING FROM 0 TO 4-FEET IN DEPTH SHALL BE INSTALLED FROM A WORKING BENCH CUT APPROXIMATELY 4 FEET BELOW THE TOP OF PILES. LAGGING BETWEEN THE DEPTHS OF 4 AND 0-FEET SHALL BE INSTALLED FROM A TRENCH CUT INTO THE BENCH AS NECESSARY, THEN BACKFILLED WITH ON -SITE SOILS. HEAVY EQUIPMENT SHALL NOT BE OPERATED ON THE BENCH. 19 3. WHERE REOLIMEO. GRAVEL BACKFILL SHALL BE PLACED AND COMPACTED USING RODDING TECHNIQUES 19:4. ETLCEOS EXCAVATED SOIL LLLIST BE � FR�OLi T3T SITE ABATER RPHDY SPIN GSEO OF. 2Q CLEANUP AND RESTORATION 20.1. THE CONTRACTOR SHALL BE RESPONSIBLE FOR REMOVING ALL CONSTRUCTION DEBRIS, INCLUDING EXCAVATED SHAFT SPOIL, FROM THE SITE 2(2 ALL CLEARED VEGETATION SHALL BE REMOVED FROM THE SITE 20.3. RE-VEGETATE(HYDROSEED) ALL DISTURBED AREAS OF THE SLOPE ABOVE AND BELOW THE WALL. 20.4 MINIMUM 36-INCH HIGH SAFETY RAIUNG IS REQUIRED AT TOP OF WALL (.'O BE INSTALLED BY OWNER) 21. MONITORING 211. CONTRACTOR SHALL MONITOR SELECTED PILES FOR DEFLECTION PER FIELD ENGINEER'S INSTRUCTION - MONITORING SHOULD BE CONDUCTED ON AT LEAST THREE PILES (FOR ENTIRE WALL LENGTH)SELECTEO BY THE ENGINEER, WIT1 A MEASUREMENT TOLERANCE OF APPROXWTUYI iNOI, IN REFERENCE TO BASEL•HE LOCATION. MONITORING OF EACI1 PILE SHALL CONSIST OF AT LEAST FOUR RFAOIHGS. AN INITIAL BASELINE READING IMME DIATFLY FOLLOWING PILE INSTALLATION, A SECOND READING IMMEDIATELY FOLLOWING LAGGING NSTALLATKK ANO TWO ADDITIONAL SUBSEQUENT READINGS COND=TED APPRONIMATELY THREE DAYS APAR T, OR AS DIRECTED BY THE ENGINEER. Vicinity Map APPROVED Puv+�ttNG ayotF.e.w.,► NO. arewnn,ntr Devsbgm Permit By Date r j {1 L� .a 33194 , A a C C *0 (0 X C L d u°Occ 0 SHEET REFERENCE NUINBER: G07 SHEET 1 OF 4 0 A B D ZI s � + - � �, ~ � -- ` _ = r� r+� . r rr- J r / rr rr rr f • rr � '' !!� i 1 i J rr + !r i •� _ _1 -_�_ � -'_' _�• � ' F� / r r rr r / •' r' -r r r' r' f'r '+ f r r r r r7 1 2 ! � �ai1 -- ! «.� --' �i+er �' .--^ � +lrr - ' / •• �r I .r r r r / r- r r rr� j / ! / � �.x� ter- - - -- lrrl /'ri / r r - • r rr r r r r � r f ! � s i r' r' I •f ' r ' r RFGOylr6iYFEEREr r+r rr� ` fr" � �f _r � rr� �r r' i � r' r' ^ �` `' • F y� aH4FeL MAFIAGElJiNT � r 1 � r RI�DIC�O1� Bdtlfi•OARf �- ' If O � j � r frr % . r � L • rl r rr r rr /r` r r / xAP j41i� ilAP M, .t ------ - 'E ~47P_VC(WY) I69'.'11 -yam - -_^.if ��r �•%r �r ~ Ems____ - �'1 ;$CIIIP`f13RE- '. PILE S PILE 4r .. r raRns§ r vP r Fdll1'EA9� - ' - �JA� � r _ TIMBER WALL -��� TOP OF WALL 1 - - .Iiij j �Y �! �+ _ _JprPIfA P� ELEV=165.5 = fl18 R I 1 _S o i � 1 T nPJLYIxOs•2 REMOVE B" TREE �'~ �• 5r:ULPTH�7EHa+Cd IF NEEDED , .- I/ I SWOOD FENCE _ 4•IRON FENCE BENJAMIN BRENT D I 29435 10TH AVE SW REMOVE TWO SMALL JAPANESE MAPLES 1196DO2267 IN PLANTED AREA � I FM V&L PRIOR iRT of cT er oTHFRs PATIO PLAN YD RIM=170,07 IE 4•'PVC(SE)=169.57 211, 11 BRICK PAVERS �1 r IRON FENCE II CB RIM=166.96 I IE 6•'PVC(S)=163.56 3L IE 6"PVC(E)=163.36 E 17I�t ' TEMPORARILY MOVE 'r111111 EB AND REPLACE APLE SCULPTURE PATHS WILL BE REMOVED BY OTHERS PRIOR TO S-ART CF PROJECT J V'A�L NOROCZ MOSTAFA+TAHERNE7 29439 10TH AVE SW E VE TREE 1196002260 r6P J AP LE W ST n PATH(TYP) ` STONE POND WILL BE REMOVED PRIOR TO PROJECT BY OTHERS JA MAP PROTECT CATCH BASIN AT APLE POND LOCATION STONE POND r NORTH EDGE OF HOUSE I I PROTECT iRIVEWAY WITH STEEL PLATES M� ' c� N , •YJJ •,rt�iT /u�a`n.NI���IRS/}l�.S. j� / __ _ /.Sf6 %iz �-� �9' . :ri � tea... •:• __ /.s {{•% GY� / ", � !•"-/,.•' yiii y%N r.o' ! mm %% Ate- ■■f,--5 S /H lJ /%iHf%% Li'.✓%/.L' ,rr /w �y is® 1i I■111■1�■1■Ill■19■III■1��1■In�11■111lI■i ■1■III■1I1■I11■1�■■I11■I 1 1 ■ 111■1�■I■Ill ■A1■III ■ 1� �l ■1�1■111■I■�1■Jli ■I1 ■Ill ■1 � ■■Ill■ 1 ■ 111■11 ■1■1l1 ■ ■ 111� ��i ■ 101■1i■■1■1 nl■ I11■I I■l I1■1�■1■III■ 1 ■111 ■ 1��1■I■■1■ 1l1■ 1 �� 1■Ill■11■ll 1■ I11■11 ■1111■11■1■ ill ■1 1■lll■Inl■I■■1!1■111■1 ■i■I� ■111■�■1■111■1■111■IN■■III■ 1■IJMI.■LIMME ■ir■rr■ IMEBWE■LJ■11■11110011011101 ■■■■■■■■■ ■■■■■■■■■■■■■■■■■■■■ME ■©■©■■©i■ ■■R■■ No mom■mi� ■ ■■■■■■■■ ■■ ■■■ ■■■E ■■■■ ■ r r GRADING NOTES TOTAL CUT AMOUNT=EST 280 CUBIC YARDS TOTAL FILLAMOUNT= EST 135 CUBIC YARDS I SYMBOL LEGEND =WRING LOCATION �� f H I \J = PROPOSED SOLDIER PILE = RETAINING WALL ALIGNMENT = SECTION LINE (SEE SHEET CO2) 0 ommul.] imilim SHEET REFERENCE NUMBER: c0 J7■ SHEET 2 OF 4 3 a 3 fr 9 5 F s 8 B GFGTFX71F SACF.FILLEO L CONPACLEO A'AI�N: YGL D r-------_ --'-� i' r r frr f �_' '' i ' i / I /``�• rr j r � r r �• j l � r �' � . Jr •__-y++••-_�-- �'_ i _ - r r+ r ,r '�-r'r r��•r� r/ / fr f ✓ r r rr r r+ •, r� f r l 1� Io I r I 1 / - -- -' r---- �^ r r++yfS7ALyFrLTEiCFABRiCE __ _ter _ � rr ` / r rr r' fSBEE�€TRI}7H�r8NEET] +/ / -+r .�f r rl �PI.E 21 r' /r � r 1 r r �� ,+ --1-•�� .nw-� ..i" Y ` r �/r r / i rr /' rrr I i i /r r' ! r� r r : - • % i 1 �r r .-r f�20Y� r ; `f --.. _ � "• -' ' PREI�iIY�ANh U�E.E]y9E1�:6 NAiiV� r� / �r r 7 r r �. � :' 17��I � e j Ir.�r' / /r �.'// r •• r7� ti / .-' �.r -�ilEc'ET�IT1617tlN BLOP�i' UI�Y _ v� r , ` ! rs^y P Y' r / r !• �C �•Cy ' Mir _'---- � rr f r' • -- I_��-u�.-� -- �/ � r/ !!f rrr'_ y� f 7 r/ Jrr �/ l,f /r �ri� .- _ r • l _---- _ - ---- _ ! � !, ''r• �• ,, r I�f;/' J I. 11���- +� _r-- r AP JAP MA ! :•'7C•, I' �• �� rrr J �'___ _- --.-_ - _• .'` ''`ram � __� - ---� �!=_4_@1YJ��'.b9.� +�, = Low fir � - --• -.-• -- - APPROXIMATEa�. -1 . • - - . _ _.. _ _ ._ rrF Ir _ /� -- AT PROPOSED SOLDIER PA.E°VYALI. LUG.L �f. _ 1r TIMBER WALL — TOP OF WALL I I) r^ Y ELEV=165.5 --\-' -�~ PILES PoLi.e �'�'_ •�_ _ Poi APLEi T j• i SWOOD FENCE I I PL9NTED AREA BENJAMIN BRENT D 4'IRON FENCE 29435 10TH AVE SW 1196002267 DECK I rr efryi MLiY Ir pN 1 O C >s va IW (EW4E-ARAM WJ IIW plplp6• +toe 1111N. TFnM4 smpmilt � w v,,�1vEa r rA E •' .• ,off} � i o to w r..I BRICK PAVERS IRON FENCE CB RIM=166.96 IE 6••PVC(S)=163.56 IE 6'•PVC(E)=163.36 +a SCULPTURE aPPAOXiMATEDISTURBANCELIMIT YD RIM=170;07 IE 4"PVC(SE)=169-57 � Y/A _ MAPLE JA MAP LE PILE STACaING AREA EROSION AND SEDIMENTATION NOTES 1. Approval of this erosion and sedimentation (ESC) plan does not constitute an approval of permanent road to drainage design (e.g. size and location of roads, pipes, restrictors, channels, retention facilities, utilities, etc.). 2. The implementation of these ESC plans and the construction, maintenance, replacement, and upgrading of these ESC facilities is the responsibility of the applicant/ESC supervisor until all construction is approved. 3. The existing driveway will serve as the stabilized construction entrance and will be mainlained in this capacity for the duration of construction. The right-of-way will be kept clean of sediment. Any tracked sediment will be promptly cleaned off of the right-of-way with the use of shovels or sweeping. 4. The ESC facilities shown on this plan must be constructed prior to or in conjunction with ali clearing and grading so as to ensure that the transport of sediment to surface waters, drainage systems, and adjacent properties is minimized. 5. The ESC facilities shown on this plan are the minimum requirements for anticipated site conditions. During the construction period, these ESC facilities shall be upgraded as needed for unexpected storm events and modified to account for changing site conditions (e.g. additional cover measures, additional sump pumps, relocation of ditches and silt fences, perimeter protection etc.) as directed by the City of Federal Way. �1 ASNE£OED) JAP At LE NOROOZ MOS-rAFA+7AHERNE2 29439 10TH AVE SW 1196002260 I• JAP WPLE -- STO PATH(TYP) ACCESS TO SITE R.IMr1E"E TEMPORARY CONSTRUCTION ENTRANM STONE POND PLACE STEEL PLATES TO PROTECT EXISTING CONCRETE DRIVEWAY (TEMPORARY CONSTRUCTION ENTRANCE) ?-M-r6 1 6. Any areas of exposed soils, including roadvray embankments, that will not be disirlbuted for two consecutive days during the vmI sea sari or seven days during the dry season shall be immediately stabilized with the approved ESC methods (e.g. seeding, mulching, plastic covering, etc.). 7_ Any area needing ESC measures that do riot require immediate attention shall be addressed within seven (7) days. S. The ESC facilities on inactive sites shall be inspected and maintained a minimum of once a month during the dry season, bi-monthly during the wet season, or within twenty four (24) hours following a storm event. 9. At no time shall concrete, concrete -by-products, vehicle fluids, paint, chemicals, or other polluting matter be permitted to discharge to the temporary or permanent drainage system, or to discharge from the project site. 10.Establish for hydroseed or other permanent plantings or ground cover. A U N 8 0 s� w C O 7e C C � CiL m 'O o m C rn W C LL C °c O o O W SHEET REFERENCE NUMBER: CO3 SHEET 4 OF 4 GEOTECHNICAL REPORT Cannon Slope Protection 29437 10th Ave SW Federal Way, Washington 98023 Prepared for: Marty and Katherine Cannon Project No. 150376 • August 31, 2016 '%Aspect CONSULTING GEOTECHNICAL REPORT Cannon Slope Protection 2943710th Ave SW Federal Way, Washington 98023 Prepared for: Marty and Katherine Cannon Project No. 150376 • August 31, 2016 Aspect Consulting, LLC Henry H. Haselton, PE Principal Geotechnical Engineer hhaselton@aspectconsulting.com Jesse G. Favia, LG Senior Staff Geologist jfavia@aspectconsulting.com Dave H. McCormack, LEG Senior Associate Engineering Geologist dmccormack@aspectconsulting.com w:\ GEOTECHM0376 Cannon Residence Slope Recon\Deliverables\Geotech Report\CannonSlope- Geotech ReportFINAL_083116.docx ASPECT CONSULTING Contents 1 Project Summary.........................................................................................1 1.1 Project Overview........................................................................................1 2 Observations...............................................................................................3 2.1 Site Conditions and Topography.................................................................3 2.2 Geologic Mapping.......................................................................................3 2.3 Subsurface Conditions...............................................................................4 2.4 Site Geology...............................................................................................4 2.4.1 Fill......................................................................................................4 2.4.2 Colluvium..............................................................................................5 2.4.3 Landslide Deposits...............................................................................5 2.4.4 Pre -Fraser Nonglacial Deposits............................................................ 5 2.4.5 Pre -Fraser Glaciolacustrine Deposits....................................................5 2.4.6 Pre -Fraser Undifferentiated Deposits....................................................5 2.5 Groundwater...............................................................................................5 3 Geotechnical Engineering.........................................................................7 3.1 Seismic Design Considerations.................................................................. 7 3.2.1 Cantilevered Soldier Pile Wall Design...................................................7 3.2.2 Soldier Pile Wall Installation..................................................................9 3.3 Slope Stability Analysis............................................................................10 3.4 Shoreline and Critical Area Considerations.............................................12 3.5 Construction Considerations.....................................................................13 3.5.1 Cantilevered Soldier Pile Wall...........................................................13 3.5.2 Lagging............................................................................... .......13 3.5.3 Earthwork Considerations...................................................................14 3.5.4 Temporary and Permanent Slopes....................................................14 3.5.5 Erosion Protection and Vegetation Management..............................15 3.6 Additional Project Design and Construction Monitoring ............................16 3.6.1 Construction Sequence and Schedule...............................................16 3.6.2 Nonload-Bearing Zones......................................................................16 3.6.3 Inspection and Maintenance...............................................................16 4 References.................................................................................................18 Limitations.........................................................................................................19 PROJECT NO. 150376 • AUGUST 31, 2016 ASPECT CONSULTING List of Tables 1 Summary of Earth Pressures for Design of the Cantilevered Soldier Pile Wall 2 Summary of Soil Engineering Properties Used in Slope Stability Analyses 3 Summary of Slope Stability Analyses Results List of Figures 1 Vicinity Map 2 Site and Exploration Plan List of Appendices A Soil Boring Logs B Laboratory Results C Slope Stability Analyses D Structural Calculations E Project Plans F Ecology Well Log PROJECT NO. 150376 • AUGUST 31, 2016 1 Project Summary This report presents the results of a slope protection design (Project) performed by Aspect Consulting, LLC (Aspect) at the Cannon residence located at 29437 1 Oth Ave SW, Federal Way, Washington (Site). The Project location is shown on Figure 1 — Site Vicinity Map and Sheets GO and COI of the project plans (Appendix E). The Project is detailed in Project plans GO and COI through CO3 in Appendix E. Aspect performed three phases of work in support of the Project: • A geotechnical reconnaissance and subsurface exploration program; • A slope protection analysis; and, ■ Final design analysis and permitting support for the selected slope protection alternative. The purpose of the Project is to protect the backyard from shallow landslide events within the upper portion of the steep slope at the Site. The Project is not designed for lower frequency (less likely) deep-seated landslide risks, nor the stability of the mid -slope and lower slope areas below the Site. This report summarizes the results of the completed field explorations, the stabilization alternatives, and geotechnical engineering design recommendations for the selected alternative, which is detailed in Appendix E. It also includes recommendations for inspection and maintenance of the slope stabilization system. Because the proposed Project is located within City of Federal Way (City) shoreline jurisdiction and mapped steep slope -related critical areas, permitting for the Project will require a shoreline exemption. It is our opinion that the Project, will not directly impact beach nourishment or feeder bluff shoreline processes, nor will it negatively impact adjacent properties or critical areas. 1.1 Project Overview The Cannon residence lies near to the top of a steep slope above Puget Sound. In the fall of 2015 a shallow landslide occurred about 50 feet north of the residence on the upper slope. We conducted an initial assessment after the slide and concluded that the slide was caused by natural weathering of soils that form the core of the hillside, combined with recent heavy rain. Additionally, surficial, shallow landslides affecting about the upper 3 to 5 feet of the slope will continue to occur reducing the setback of the residence from the top of the steep slope, eventually requiring mitigation/stabilization measures to protect the residence. We considered the relative risks of the shallow and deep-seated landslide hazards at the Site; and provided our opinion that the greatest risk to the Site was from the smaller, but more frequent, shallow landslides rather than from the larger, but much less frequent, deep-seated landslides. In our opinion, there is no practical or economical way to mitigate PROJECT NO. 150376 • AUGUST 31, 2016 ASPECT CONSULTING the deep-seated landside hazards at the Site. The shallow landslide hazards can be mitigated, and we recommend stabilization of the upper portion of the steep slope to protect the property from future shallow landslides. Based on the results of our reconnaissance and subsurface exploration, we considered two options to stabilize the upper slope at the Site; an anchored mesh grid supported by soil nails or a cantilevered soldier pile wall. A conceptual feasibility study comparing these options indicated that the cantilevered soldier pile wall option provided a more cost-effective solution to protect the upper yard area from shallow landslide activity. In consultation with the Cannons, a soldier pile wall was selected as the preferred stabilization alternative for the Site. During the design phase, we refined our analysis to design a cantilevered (meaning no tieback anchors are required) soldier pile wall. The wall will include steel h-beams that are 40-feet-long and embedded in drilled shafts backfilled with lean concrete. The exposed portion of the wall will include timber lagging spanning between the h-beams. Over decades, we anticipate that shallow landslides will continue to occur downslope of the wall, thereby episodically increasing the exposed height of the wall. The wall is designed to accommodate two approximately 4-foot-thick (the typical thickness of observed and reported recent landslides) shallow landslide events, to a maximum exposed height of 8 feet. This approach is designed to provide decades -worth of protection to the adjacent upslope yard area. The cantilevered soldier pile wall will be installed by excavating a bench to a depth of 4 feet below the top of the wall. This bench will provide a working area for wall construction, reduce the driving forces on the weak soils in front of the wall, and reduce future slide hazards. From this bench, lagging will initially be installed to six feet below the top of the wall by locally trenching an additional 2 feet below the bench and then backfilling the trench. In the future, lagging may be installed an additional two feet below the bottom of the exposed wall (for a total wall height of 8 feet) as needed. Additional timber lagging may be installed by any qualified earthwork contractor The protection lifespan of the wall may be further extended by installing a row of tieback anchors at a later date. The wall is designed such that, once the exposed portion of the wall reaches the maximum cantilever design height of 8 feet, a single row of tiebacks can be installed (ideally at a depth of about 8 feet below the top of the wall) in order to extend the maximum exposed height of the wall to approximately 18 vertical feet. We conducted initial analyses to confirm feasibility of this tieback anchor concept; however, the scope of this Project did not include detailed tieback anchor design. PROJECT NO. 150376 • AUGUST 31, 2016 2 Observations 2.1 Site Conditions and Topography The Site is located northwest of Federal Way on the southern shore of Poverty Bay overlooking Puget Sound (Figure 1, Site Vicinity Map). The Site is approximately 1.18 acres, rectangular shaped, and oriented in a south -to -north direction. The Site is bordered by developed residential properties to the east, west, and south, and by Puget Sound to the north. The Site layout, topography, and the locations of the completed subsurface explorations are shown on Figure 2, Site Exploration Map. The Site slopes south to north from about Elevation 180 (feet NAVD88) at the southern edge of the property line to Elevation 10 and extends into Puget Sound. Topographic relief is about 180 feet across the site. The steep northern slope is gently convex from east to west and includes an approximately 20-foot-wide unvegetated slope extending to near the base of the slope from the previous shallow landslide. 2.1.1 Fall 2015 Landslide In November 2015, Aspect conducted Site reconnaissance of the landslide area and provided preliminary mitigation recommendations. The recent slide that we observed was a shallow colluvial landslide roughly 25 feet wide by several feet deep. The slide extended from the top of the steep slope to at least the mid -slope. Heavy rains prior to the slide event weakened the soft to medium stiff fill, colluvial soils, and landslide debris in the shallow subsurface (see geotechnical logs, Appendix A). These soils reached critical saturation where the weight of the soils overcame the soil strength and the soils were no longer stable on the steep slope. Slope stability was also decreased by the lack of a dense and deep tree and shrub root network on the upper slope. Topography of the slope indicated that there have been older slides to the south of the active slide. The soil strength in an area of the steep slope to the north of the active slide was qualitatively assessed with a T-probe rod and was noted to be very weak and notably weaker than the nearby soils that compose the uplands. Weak surface soils on steep slopes are common and indicate that those areas are also prone to surficial slides. Bare soils exposed by the slide had been covered with straw as a temporary erosion control measure. There were no obvious indications of tension cracks east of the fence that would signal the start of another slide that would extend significantly farther inland. 2.2 Geologic Mapping The Lidar-Revised Geologic Map of the Poverty Bay 7. S' Quadrangle, King and Pierce Counties, Washington (USGS Scientific Investigations Map SIM-3317; Tabor et al, 2014) indicates that the Site is primarily underlain by pre -Olympia age coarse -grained and fine-grained deposits with interbedded pre-Vashon till deposits. Pre -Olympia coarse - grain deposits are described as oxidized sand and gravel containing local lenses of sand silt. Pre -Olympia fine-grained deposits are described as laminated silt and clay with PROJECT NO. 150376 • AUGUST 31, 2016 ASPECT CONSULTING widely scattered organic material. Pre-Vashon till deposits are described as diamict silt, sand, and gravel dominant. 2.3 Subsurface Conditions Subsurface conditions at the Site were inferred from the completed field reconnaissance, subsurface explorations, review of applicable geologic literature, and our experience with the local geology. Three machine drilled borings, B-1, B-2, and B-3 and one hand drilled boring, HA-1, were completed between February 29, 2016 and March 1, 2016. Field exploration methods for the four subsurface borings are included in Appendix A. Detailed descriptions of the subsurface conditions encountered in our explorations, as well as the depths where characteristics of the soils changed, are indicated on the soil boring logs presented in Appendix A. The depths indicated on the log where conditions changed may represent gradational variations between soil types. Soils were classified per the Unified Soil Classification System (USCS) in general accordance with the American Society for Testing and Materials (ASTM) D-2488, Standard Practice for Description and Identification of Soils (Visual and Manual Procedure). A key to the symbols and terms used on the logs is provided in Figure A-1. Laboratory test results of selected subsurface samples are shown in Appendix B. Laboratory testing was conducted in order to determine natural moisture content, grain size distribution, and/or plasticity, which were used to develop our assumptions about soil properties of geological units. Laboratory testing indicated that Site fill was typically high plasticity clay and nonglacial lacustrine deposits and glaciolacustrine deposits were generally nonplastic to low -plasticity silt, as shown in more detail on the borings logs in Appendix A. 2.4 Site Geology Our subsurface explorations confirm that the Site is immediately underlain by glacially overridden and nonglacially overridden, predominantly fine-grained sediments. The subsurface soils, based on our interpretation of the completed subsurface explorations (described in detail in Appendix A), can be grouped into six soil units consisting of the following from the top layer down: normally consolidated (not glacially overridden) fill, colluvium, and landslide deposits, glacially consolidated (glacially overridden) deposits of nonglacial and glacial (glaciolacustrine) origin, and undifferentiated pre -Fraser deposits. 2.4.1 Fill We encountered fill at the ground surface down to 4.5 feet below ground surface (bgs) in borings B-1 and B-3. Fill ranged from soft to medium stiff, moist to very moist, high plasticity clay (CH) 1, typically with trace sand and between 1 and 10 percent organic content. 1 Soil Classification per the Unified Soil Classification System (USCS). Refer to ASTM D2488 (See Appendix A). 4 PROJECT NO. 150376 • AUGUST 31, 2016 2.4.2 Colluvium We encountered colluvium at the ground surface down to a maximum of 4.5 feet bgs in the boring on the steep slope (HA-1). Colluvium was soft, very moist, low to moderate plasticity silt (ML) and typically contained numerous roots and slight iron -oxide alteration. 2.4.3 Landslide Deposits We encountered landslide deposits at the ground surface or below the colluvium down to 7 feet below ground surface (bgs) in borings B-2 and HA-1. The landslide deposits ranged from medium stiff to stiff, very moist to wet, non -plastic to low plasticity silt (ML), typically with trace sand and between 1 and 10 percent organic content. Disturbed relict bedding laminations were occasionally observed. 2.4.4 Pre -Fraser Nonglacial Deposits We encountered pre -Fraser nonglacial deposits below fill or landslide debris to 18.5 feet bgs in borings B-1, B-2, and B-3. Nonglacial deposits were typically stiff to very stiff, moist to very moist, non -plastic or low plasticity silt (ML), typically thin sand or low - plasticity clay laminations were occasionally inclined to the core axis up to 45 degrees. The unit includes rare iron -oxide staining and rare thin fracture zones up to 0.3 feet thick. 2.4.5 Pre -Fraser Glaciolacustrine Deposits We encountered glaciolacustrine deposits below nonglacial lacustrine deposits to the bottom of borings B-1, B-2, and B-3. Glaciolacustrine deposits were very stiff to hard, moist to wet, non -plastic to low plasticity silt (ML), with occasional thin laminations of fine silty sand (SM) or low -plasticity clay (CL). The unit includes rare iron -oxide staining and rare thin fracture zones up to 0.4 feet thick. Nonglacial deposits and glaciolacustrine deposits were deposited before the advance of the most recent glacial ice -sheet advance, and likely correspond to the pre -Fraser fine- grained glacial deposits (Qpgof) of Tabor et al (2014). 2.4.6 Pre -Fraser Undifferentiated Deposits Pre -Fraser deposits below the extent of the completed subsurface explorations were observed during field reconnaissance. These deposits were typically very stiff to hard, moist to wet, interbedded sandy SILT (ML) and silty SAND (SM). 2.5 Groundwater Groundwater was encountered in borings B-1, B-2, and B-3 and we measured the static water levels during drilling (see Appendix A for summary of the boring logs). The water levels were measured on February 29, 2016 between 15 feet bgs and 20 feet bgs below the upland, at 10 feet bgs below the upper slope, and at 4 feet bgs below the mid -slope. Water levels become closer to the ground surface downslope between Elevation 161 and Elevation 141 (feet NAVD88). As measured during drilling, the upper 40 feet to 60 feet of soils bgs were saturated with water content decreasing with depth. Deeper groundwater at the Site was interpolated between Puget Sound and a water well about 1 mile to the southeast (see Appendix F for Ecology well log). PROJECT NO. 150376 • AUGUST 31, 2016 ASPECT CONSULTING The groundwater should be expected to fluctuate in depth and flow volume as affected by seasonal conditions, site usage, variations in rainfall, irrigation, and other factors. Based on our observations, the groundwater conditions at the Site will be similar or lower in elevation to conditions observed at the time of drilling during the dry summer season. Additionally, it is possible that shallow perched groundwater will be present during the winter wet season, or following prolonged storms. PROJECT NO. 150376 • AUGUST 31, 2016 3 Geotechnical Engineering The proposed Project will not negatively affect the stability of the mapped geologically hazardous area or shoreline located at and near the Site provided the recommendations contained herein are incorporated into the design and construction of the Project. 3.1 Seismic Design Considerations The proposed slope protection is designed to preserved the yard between the residence and the steep slope and is not intended to provide direct protection of the residence. Since the proposed slope protection will not directly impact the residence, seismic design is not required by code (Section 15.6.1 of ASCE-7-10). We determined the seismic design criteria for the proposed slope protection based on a recurrence interval over the expected life of the slope protection that would satisfy the owner's individual risk tolerance. The owner has elected to include slope protection against a modest earthquake event with a 50 percent probability of recurrence in 75 years. Using the USGS National Seismic Hazards Mapping Program Probabilistic Seismic Hazards Analysis Interactive Deaggregations tool (USGS, 2008), we determined the peak ground acceleration for an event with a 108 year return period. The lateral seismic component, kh, was calculated as 0.07 based on peak ground acceleration of 0.14. 3.2 Slope Protection Alternatives Selection Our initial conceptual design focused on two protection alternatives: a soil nail -anchored mesh to reinforce the upper slope or a cantilevered soldier pile wall to retain the top of the upper slope. We found that the anchored -mesh soil nail option could potentially provide similar protection of slope soils under static conditions to a cantilevered soldier pile wall option; however, the Site soil and topographic conditions were not optimal for the soil nail design concept and would have required a tightly spaced (and therefore costly) soil nail pattern in order to stabilize the slope to an acceptable level. The soldier pile wall alternative was selected as a more cost-effective option, intended to insulate the upper yard area from the shallow characteristic slope failures that will continue to occur downslope of the wall. 3.2.1 Cantilevered Soldier Pile Wall Design We recommend a cantilever soldier pile shoring wall with an ultimate exposed wall height of 8 feet as the most cost-effective slope protection option. Based on our characterization of the Site and our observations, we anticipate the wall will support and retain the fill, landslide debris, and upper nonglacial deposits. The embedded portion of the wall will gain support from the very stiff and hard non -glacial and glaciolacustrine deposits. The cantilevered soldier pile wall should initially be installed to an exposed height of 6 feet below the top of the wall. To conform with OSHA requirements for exposed soil faces, a bench to a maximum of four feet below the top of the wall should be excavated to use as a working platform. Four feet of lagging will be installed from the bench before PROJECT NO. 150376 • AUGUST 31, 2016 ASPECT CONSULTING excavating a temporary trench an additional 2 feet below the bench. Two feet of lagging will be installed below the bench for a total of 6 feet of lagging below the top of the wall. In the future, lagging may be installed an additional two feet below the bottom of the exposed wall (for a total wall height of 8 feet) as needed. The temporary trench will be backfilled with native soils leaving a bench four feet below the top of the wall. Leaving this bench after wall construction will reduce the driving forces on the weak soils in front of the wall and reduce the slide hazard and provide a working surface for future maintenance activities if needed. The soldier pile wall should be installed as a permanent system. The soldier piles should be designed for a maximum retained height of 8 feet with an initial height exposed height of 4 feet and with a maximum center -to -center spacing of approximately 8 feet. If the ultimate wall height of 8-feet is reached, tieback anchors may be designed and installed to extend the life of the wall. We recommend designing the soldier pile wall based on the following earth pressures: Table 1—Summary of Earth Pressures for Design of the Cantilevered Soldier Pile Wall Depth Range feet below top of wall Active Earth Pressure (1)(2) c Passive Earth Pressure pc 0 to 5 38 N/A 5 to 8 32 N/A Greater than 8 32 140 Notes: pcf = pounds per cubic foot. (1) Presented as an equivalent fluid pressure, assumes a cantilever wall system. (2) Assumes a level backslope behind the wall, sloping foreslope in front of the wall, and ignores any passive resistance from the fill deposits. We designed the cantilevered soldier pile wall using equivalent fluid earth pressures that assume the wall is allowed to yield slightly and invoke the "active" condition. We calculated equivalent fluid earth pressures using the soil engineering properties in Table 2. Earth pressure calculations are included in Appendix D. The use of free -draining lagging and wall facing is anticipated such that there will be no buildup of unbalanced hydrostatic pressures behind the wall. The active earth pressures act over the full soldier pile spacing above the base of the wall and over the soldier pile hole diameter (B) below the base of the wall. The passive pressures act over two and half times the soldier pile hole diameter (2.513) for the embedded portion of the wall. The passive resistance provided is ultimate and should include a factor of safety of 1.5. The passive resistance value accounts for the adverse slope condition below the toe of the wall. Passive resistance was ignored to a depth of 8- feet below the top of the wall, to account for possible future landslides. Seismic design of the wall considered a reasonable expectation of earthquake occurrence during its anticipated life. Using the USGS Interactive Deaggregations, we determined the peak ground acceleration for an event with a 50 percent probability in 75 years (108 year return period). The lateral seismic component, kh, was calculated as 0.07 based on peak ground acceleration of 0.14. PROJECT NO. 150376 • AUGUST 31, 2016 Using the above design criteria, we conducted a soldier pile wall analysis using Shoring Suite, a computer program by CivilTech (2015; Appendix D). The basic wall design consists of 40-foot-long steel soldier pile beams (HP12 x 53 or equivalent) installed in minimum -diameter 24-inch augered holes, stabilized in place by minimum 1,000 psi lean -mix concrete, and spaced 8 feet apart. Timber lagging will be installed in 8-foot spans between h-beams to a height of 6 feet below the top of the wall. In the future, lagging may be installed an additional two feet below the bottom of the exposed wall (for a total wall height of 8 feet), as needed. Complete wall design criteria, and installation details and notes are included in Project design plan sheets (Appendix E). We met on -Site with a soldier pile wall contractor early in the design phase in order to ensure the basic constructability of our design concept. 3.2.2 Soldier Pile Wall Installation All soldier pile installation activities should be observed by the geotechnical engineer. Since the soldier pile wall is a permanent system, the soldier piles should be epoxy coated (or equal) for corrosion protection a minimum of 2 feet below the projected final grades. Alternatively, the piles may be oversized to compensate for loss of material over the wall design life. The soldier piles will penetrate through loose to stiff fill, landslide debris, and nonglacial lacustrine deposits and be embedded into stiff to hard non -glacial lacustrine and glaciolacustrine deposits. Although not observed during our reconnaissance of the Site and previous evaluations, our local engineering experience indicates that the lacustrine and glaciolacustrine deposits may contain isolated large obstructions that could be obstructions to the drilling and installation of the soldier piles. The Contractor should be prepared to remove obstructions and/or have contingencies for alternate soldier pile locations and wall configurations if an obstruction cannot be removed. Groundwater should be anticipated within the nonglacial lacustrine and glaciolacustrine deposits and the Contractor should be prepared to drill soldier piles such that caving is prevented. Preventative measures to mitigate for caving and hole collapse for a drilled scenario may include a temporary casing and/or drilling fluids. If groundwater is encountered and/or drilling fluids are used, we recommend the shaft backfill consist of pumpable lean concrete placed with a tremie pipe to the bottom of the shaft. Soldier piles with center -to - center spacing of less than three pile diameters should not be drilled in sequence. Rather, every other pile should be drilled, and the concrete should be placed and allowed to cure at least 24 hours before adjacent piles are drilled. Once the soldier piles have been installed and accepted by the geotechnical engineer, excavation may begin. Excavation should proceed along the entire face of the wall to approximately the same elevation, and should not exceed an open -face depth of 4 feet before installing lagging. The soil in front of the wall should be excavated to allow for lagging installation to 6 feet below the top of the wall. Lagging should be added as - needed when additional sloughing occurs along the slope. The front of the wall should be backfilled with native soil upon completion of the lagging installation. Any voids behind the lagging should be replaced with self -compacting and free -draining materials such as pea gravel. To ensure free -draining conditions, spacers should be used between lagging PROJECT NO. 150376 • AUGUST 31, 2016 ASPECT CONSULTING elements. Spacing between lagging will provide suitable drainage to avoid unbalanced hydrostatic pressure behind the wall. 3.3 Slope Stability Analysis 10 Based on our review of the existing topography, our field observations, and subsurface exploration data, we conducted stability analyses of the critical section of the steep slope using the computer model SLIDE (Rocscience, 2013). Our stability analyses were conducted based on a critical section though the steepest part of the slope immediately east of the unvegetated landslide area, in the location shown on Figure 2. The detailed results of the stability analyses are shown in Appendix C. The soil engineering properties assumed for the model are summarized on Table 2 below. Table 2—Summary of Soil Engineering Properties Used in Slope Stability Analvses and Cantilevered Wall Desian Strength Parameters Geologic Unit Total Unit Weight (pcfl( - Friction Angle Cohesion (deg•)0) (Psf)(" Fill 105 26 0(2) Colluvium 105 30 25 Landslide Deposits 115 32 0(2) Pre -Fraser Nonglacial and 120 35 100(3) Glaciolacustrine Deposits Pre -Fraser Undifferentiated 120 36 100(3) Deposits Notes: 1) pcf = pounds per cubic foot; psf = pounds per square foot; and deg = degrees. 2) Apparent cohesion increased to 50 psf during short term (seismic) loading conditions. 3) Apparent cohesion increased to 200 psf during short term (seismic) loading conditions. The engineering properties summarized in Table 2, and used in our analyses, are primarily based on our experience in similar materials settings with similar geologic materials and back calculations of the existing conditions. Back calculations of the existing slope configuration indicate the values assumed are conservative. Structure loads for the residence structures were estimated using Chapter 16 of the 2012 IBC (IBC, 2012) and Table C3-1 from the ASCE Standard 7-10. A conservative surface load of 400 psf was applied within the residence footprint for the purposes of the slope stability analysis. The SLIDE program performs slope stability computations based on the modeled slope conditions and calculates a factor of safety against slope failure, which is defined as the ratio of resisting forces to driving forces. A factor of safety of 1.0 indicates a "just -stable" condition, and a factor of safety less than one would indicate unstable conditions. PROJECT NO. 150376 • AUGUST 31, 2016 We utilized Spencer's method in our SLIDE analyses. For the final design, we modeled a cantilevered soldier pile retaining wall with conservative shear strength of 102.66 kips per foot, which accounts for a 1.5x safety factor. The shear strength of the steel h-beams was averaged over a typical center -to -center pile spacing of 8 feet. Selected slope stability analyses for the selected cantilevered wall design along with assumed soil parameters and model conditions are included as Appendix C. PROJECT NO. 150376 • AUGUST 31, 2016 11 ASPECT CONSULTING Table 3—Summary of Slone Stability Analyses Results Existing Existing ProposedP) Proposed(3) Location Static Factor Seismic0) Factor Static Factor of SeismicM Factor of Safety(2) of Safety(') Safety(2) of Safet IZ► Edge of Slope South of j 0.9 0.9 1.3 1.1 Proposed Wall Edge of Slope North of 1.1 I 1.0 1.1 1.0 F Proposed Wall Notes: (1) Pseudostatic seismic analysis utilize a seismic coefficient (kh) of 0.07g. (2) Factor of Safety —The minimum FS at the location indicated found using Spencer's method in computer program SLIDE. (3) Cantilever soldier pile wall protection. Results of our slope stability modeling show the addition of a cantilevered wall increases safety factors for failure planes initiating south of (behind) the wall and exiting on the upper and mid -slopes. Safety factors for failure plane similar to the landslide event in November 2015 are increased from 0.9 factor of safety (F.S.) to 1.1 F.S. with the addition of a cantilevered wall at the top of the slope. The slope stability results indicate that the areas south of the proposed wall including the lawn can be effectively stabilized by the proposed wall. Safety factors at the northern edge of the residence are the same with the addition of the cantilevered wall. The stability of the areas to the north of the proposed wall will be unchanged and continued landslide activity should be anticipated. 3.4 Shoreline and Critical Area Considerations The proposed Project is located within the shoreline jurisdiction managed by the City; however, it is exempt from shoreline substantial development permit (SSDP) provisions per Washington Administrative Code 173-27-040(2)(g). The Project is located within 25 feet of critical areas defined by Federal Way Revised Code (FWRC) 15.05.030 and requires a shoreline exemption application that addresses erosion hazard and landslide hazard critical areas in F)AIRC Titles 15 and 19. We anticipate that any temporary disturbance of soil and vegetation will be relatively self-contained within the Site, and that the Site will be promptly revegetated following construction. The proposed cantilevered soldier pile wall will not stop mass wasting processes from happening downslope of the wall and will continue to allow sediment delivery to the beach and beach nourishment typical of feeder bluffs. The nearshore processes will not be affected by the proposed cantilever wall and the Project will not directly impact shoreline processes. The Project will not result in the creation of any new impervious surface, and also will not increase surface water discharge or sedimentation to adjacent properties beyond predevelopment conditions. 12 PROJECT NO. 150376 • AUGUST 31, 2016 3.5 Construction Considerations 3.5.1 Cantilevered Soldier Pile Wall The soldier piles must be properly constructed in order to perform as designed. We make the following recommendations for soldier pile construction: • Perched groundwater or caving soil may be encountered during drilling of soldier piles shafts, and the contractor should be prepared to use appropriate methods to prevent caving and soil loss. If there is standing water in the completed shaft, concrete should be placed with a tremie pipe placed at the bottom of the hole. • Soldier piles with center -to -center spacing of less than 3 pile diameters should not be drilled in sequence. Rather, every other pile should be drilled, and the concrete should be placed and allowed to cure at least 24 hours before adjacent piles are drilled. • The bottom of the soldier piles shafts should be relatively undisturbed glacially consolidated soils and should be cleared of loose soils or slough that may have accumulated during drilled prior to installing the soldier pile. ■ A qualified geotechnical engineer should provide special inspection services during soldier pile installations. Special inspection should include monitoring pile shaft drilling, acceptance of the pile shafts, and inspection of the pile and concrete installation. Acceptance of the soldier pile installation should be the responsibility of the geotechnical engineer. • Since the soldier pile wall is a permanent system, the soldier piles should be epoxy coated (or equal) for corrosion protection a minimum of 2 feet below the projected final grades. Alternatively, the piles may be oversized to compensate for loss of material over the wall design life. 3.5.2 Lagging Timber lagging should be a minimum of 4-inches-thick and 6-inches-wide, new treated Douglas Fir or Larch of grade number 2 or better. We recommend treatment with a water -based wood preservative. The lagging boards should be installed with a minimum gap of one -eighth inch between boards. Excavation should not exceed an exposed height of 4 feet before installing lagging. When the first level of lagging is complete, the contractor can continue with the excavation and lagging in 4-foot lifts until all required lagging has been installed. The soil in front of the wall should be excavated to allow for lagging installation to a minimum of 6 feet below the top of the wall. Lagging should be added as -needed when additional sloughing occurs along the steep slope. In the future, lagging may be installed an additional two feet below the bottom of the exposed wall (for a total wall height of 8 feet) as needed. The front of the wall should be backfilled to 4 feet below the top of the wall with native soil to the design finish grade upon completion of the lagging installation If caving, sloughing, or slickensided soils are encountered during excavation, the contractor should be prepared to install the lagging in short vertical increments and PROJECT NO. 150376 • AUGUST 31, 2016 13 ASPECT CONSULTING backfill behind the lagging to fill voids. Voids should be backfilled the same working day. Any voids behind the lagging should be replaced with self -compacting and free -draining materials such as pea gravel. To ensure free -draining conditions, spacers should be used between lagging elements. Spacing between lagging will provide suitable drainage to avoid unbalanced hydrostatic pressure behind the wall. 3.5.3 Earthwork Considerations Earthwork is typically most economical when performed under dry weather conditions. Appropriate erosion control measures should be implemented prior to beginning earthwork activities in accordance with the local regulations. In our opinion, excavation can generally be accomplished using standard excavation equipment. While not directly observed in our subsurface explorations, the presence of potential obstructions in fill should be anticipated. If earthwork is to be performed or fill is to be placed in wet weather or under wet conditions when soil moisture content is difficult to control, the following recommendations apply: • Earthwork should be performed in small areas to minimize exposure to wet weather. Excavation or the removal of unsuitable soils should be followed promptly by the placement and compaction of clean structural fill. The size and type of construction equipment used may have to be limited to prevent soil disturbance; • The ground surface within the construction area should be graded to promote runoff of surface water and to prevent the ponding of water; • The ground surface within the construction area should be covered or sealed, and under no circumstances should be left un-compacted and exposed to moisture. Soils that become too wet for compaction should be removed and replaced with clean granular materials; • Excavation and placement of fill should be observed by the geotechnical engineer to verify that all unsuitable materials are removed and suitable compaction and site drainage is achieved; and • Appropriate erosion and sedimentation best management practices (BMPs) should be strategically implemented in accordance with the City of Federal Way BMPs. 3.5.4 Temporary and Permanent Slopes Maintenance of safe working conditions, including temporary excavation stability, is the responsibility of the contractor. All temporary cuts in excess of 4 feet in height that are not protected by trench boxes, or otherwise shored, should be sloped in accordance with Part N of Washington Administrative Code (WAC) 296-155 (WAC, 2009). With time and the presence of seepage and/or precipitation, the stability of temporary unsupported cutslopes can be significantly reduced. We recommend planning the construction schedule to have excavation occur during the summer months and to minimize the amount of time that the temporary slopes will be unsupported during 14 PROJECT NO. 150376 • AUGUST 31, 2016 construction. The contractor should monitor the stability of the temporary cutslopes and adjust the construction schedule and slope inclination accordingly. Vibrations created by traffic and construction equipment may cause caving and raveling of the face of the temporary slopes. In general, shallow surface, fill soils that will be subject to excavation and sloping on the Site classify as Occupational Safety and Health Administration (OSHA) Soil Classification Type C. These soils are will be expected to fail at steep angles. Glacially consolidated soils that will be subject to excavation and sloping below fill soils on the Site classify as OSHA Soil Classification Type B. Temporary excavation side slopes (cut slopes) are anticipated to stand as steep as 1'/2H:1 V (Horizontal:Vertical) within the fill and landslide deposits and IH:1V within the cohesive glacially consolidated soils (nonglacial lacustrine deposits and glaciolacustrine deposits). The cut slope inclinations estimated above are for planning purposes only and are applicable to excavations without inflowing perched groundwater or runoff. 3.5.5 Erosion Protection and Vegetation Management Temporary erosion protection should be installed prior to or in conjunction with all clearing and grading to minimize sediment transport to surface waters, drainage systems, and adjacent properties. Temporary erosion protection should include, but not necessarily be restricted to, a filter fabric fence between 10 and 30 feet downslope from the top of the slope (approximate location of the cantilevered soldier pile wall). The filter fabric fence should consist of geotextile fabric secured to posts on a maximum 6 feet apart. See Appendix E, Project Plans for additional details. Areas disturbed during construction should be stabilized with hydroseed turf and plantings in accordance with the Project Plans (Appendix E). After the completion of the cantilevered soldier pile wall, continued landslide activity, erosion, and sloughing of the slope on the north side of the retaining wall should be anticipated. To help slow the rate of erosion, we recommend the use of native plants and vegetation. Vegetation -related factors that affect slope instability within the near -surface soils include the following (Gray and Leiser, 1982): Root Reinforcement Roots mechanically reinforce a soil by transfer of shear stresses in the soil to tensile resistance in the roots. Soil Moisture Modification Evapotranspiration and interception in the foliage limit buildup of soil moisture. Buttressing and Arching Anchored and embedded stems can act as buttress piles or arch abutments in a slope, counteracting shear stresses. PROJECT NO. 150376 • AUGUST 31, 2016 15 ASPECT CONSULTING Surcharge Weight of vegetation on a slope exerts both a downslope (destabilizing) stress and a stress component perpendicular to the slope, which tends to increase resistance to sliding. Root Wedging Alleged tendency of roots to invade cracks, fissures, and channels in a soil or rock mass and thereby cause local instability by a wedging or prying action. Windthrowing Destabilizing influences from an overturning moment exerted on a slope as a result of strong winds blowing downslope through trees. Root reinforcement, soil moisture modification (reduction), and buttressing and arching are enhancing slope stability at the Site. Surcharge, root wedging, and windthrowing will have a net destabilizing effect. Other sources of surficial slope instability include improperly managed storm and surface water runoff flowing near or over the top of the slope. We recommend maintaining dense, vegetative groundcover on the steep slope. In the event that soils on or near the steep slope become exposed through erosion and/or surficial landslide activity, we recommend aggressively revegetating the exposed area. Erosion control measures, such as hydroseed, should be utilized to minimize soil exposure and maintain slope stability. For specific vegetation recommendations, the Washington State Department of Ecology (Ecology) has several good publications on the subject including Vegetation Management: A guide for Puget Sound Bluff Property Owners (Ecology, 1993a), and Slope Stabilization and Erosion Control Using Vegetation: A Manual of Practice for Coastal Property Owners (Ecology, 1993b). This information is also available from Ecology's website. A steep -slope planting guide is also available (Ecology, 2015). 3.6 Additional Project Design and Construction Monitoring 3.6.1 Construction Sequence and Schedule Due to the Project location within a mapped Critical Area, grading and filling associated with the project may be seasonally limited to the period between May 1 and October 1. However, the City may approve a dry season extension depending on actual weather conditions. 3.6.2 Nonload-Bearing Zones After construction, excessive loading of the yard area upslope of the wall, including any filling to raise the grade above the wall, should be avoided. In general, no heavy equipment, buildings, or other loads should be placed at the top of the wall or within a 10-foot upslope buffer zone from the wall. 3.6.3 Inspection and Maintenance Both the wall and slope above and below it should be inspected annually, and following any earthquake or apparent movement on the slope below the wall. If landslides or other 16 PROJECT NO. 150376 • AUGUST 31, 2016 soil movement have occurred on the slope below the wall, the base of the wall should be inspected to make sure that the lowest row of lagging boards have not become undermined. If this occurs, a geotechnical professional should be consulted to determine if the height of the wall can be safely increased by adding additional lagging boards (the wall is designed to accommodate addition of some boards, if necessary) to the bottom, or if other modifications are appropriate. We recommend installing selected permanent monitoring points along the wall, in accordance with the Project Plans (Appendix E). These points should be surveyed within two weeks of construction, then monthly for two months after the completion of construction. The monitoring points should be permanent such that they can be measured after a strong earthquake or if soil movement is observed in the vicinity of the wall. PROJECT NO. 150376 • AUGUST 31, 2016 17 ASPECT CONSULTING 4 References American Society of Civil Engineers, 2013, Standard 7-10, "Minimum Design Loads for Buildings and Other Structures." Tabor, R.W. Booth, D.B. and K.G. Troost, 2014, Lidar-Revised Geologic Map of the Poverty Bay 7.5' Quadrangle, King and Pierce Counties, Washington, U.S. Geological Survey Scientific Investigations Map SIM-3317, scale 1:24,000. CivilTech, Inc., 2015, Shoring Suite, version 8.16f. Gray, D.H. and Leiser, A.T., 1982. Biotechnical slope protection and erosion control. Van Nostrand Reinhold Company Inc. International Building Code (IBC), 2012, International Building Code. Prepared by International Code Council, January 2012. Rocscience, Inc., 2014 Slide, version 6.029. U.S. Geological Survey (USGS), 2008, National Seismic Hazards Mapping Program Probabilistic Seismic Hazards Analysis Interactive Deaggregations tool. http://geohazards.usgs.gov/deaggint/2008/. Accessed 2016. Washington State Department of Ecology (Ecology), 1993a. Vegetation Management: A guide for Puget Sound Bluff Property Owners, 1993. Ecology, 1993b, Slope Stabilization and Erosion Control Using Vegetation: A Manual of Practice for Coastal Property Owners, 1993 Ecology, 2015, Managing Vegetation on Coastal Slopes, http://www.ecy.wa.gov/programs/sea/pubs/93-31/intro.html, 2015 18 PROJECT NO. 150376 • AUGUST 31, 2016 Limitations Work for this project was performed for Marty and Katherine Cannon (Client), and this report prepared in accordance with generally accepted professional practices for the nature and conditions of work completed in the same or similar localities, at the time the work was performed. This report does not represent a legal opinion. No other warranty, expressed or implied, is made. All reports prepared by Aspect Consulting for the Client apply only to the services described in the Agreement(s) with the Client. Any use or reuse by any party other than the Client is at the sole risk of that party, and without liability to Aspect Consulting. Aspect Consulting's original files/reports shall govern in the event of any dispute regarding the content of electronic documents furnished to others. This report and our conclusions and interpretations should not be construed as a warranty of the subsurface conditions. Experience has shown that subsurface soil and groundwater conditions can vary significantly over small distances. Inconsistent conditions can occur between explorations and may not be detected by a geotechnical study. Further geotechnical evaluations, analyses, and recommendations may be necessary for the final design of this Project. The intention of this Project is to protect from shallow landslides and not to protect from lower frequency deep-seated landslide risks, nor the stabilize the mid -slope and lower slope areas below the Site. If there is a substantial lapse of time between the submission of this report and the start of construction, or if conditions have changed due to construction operations at or near the Site, it is recommended that this report be reviewed to determine the applicability of the conclusions and recommendations considering the changed conditions and time lapse. PROJECT NO. 150376 • AUGUST 31, 2016 19 FIGURES ® ECI B-1 1 YD RIM=.159.84 `E 4"PVC(W)=169:24 8B� SCULPTURE 2-12"CH 0 RR 0 v TIMBER WALL J TOP OF WALL Q JaP '�la-PLE ELEV=165.5 _f ` 3-WOOD FENCE J PLANTED 4'TRON n AREA FENCE 0 Notes: Distances north and south to parcel boundaries from edge of image are approximate. Survey Reference: Pace Engineers, 0111912016, Topographic Survey for Marty Cannon. Eastern Property Boundary Reference: Northwest Home Designing Inc, Design 2138, Revised STONE PATH(TYP 512212002, Approved by City of Federal Way 7/17/2008 (Permit No. 08-103383-00 SF). Western Property Boundary Reference: Sadler/Bernard & Assoc. Inc, 5/6/2008, Dwg. No. 2008-054. Legend ® ECI B-1 Previous Exploration by Others ® B-1 New Explorations by Aspect f DISTANCE TO NORTH END OF PARCEL BOUNDARY; 201.75' ° DECK SHORELINE MANAGEMENT JURISDICTION BOUNDARY (PUGET SOUND ORDINARY HIGH WATER 0 (OHW) MART{ 200' NORTH) @HA-1 .� J! OJAP M, SCULPTURE j PROPERTY LINE BRICK PAVERS IRON FENCE CB RIM=166.96 IE 6"PVC(S)=163.56 IE 6"PVC(E)=163.36 -%� AP_CE I - JAP (MAPLE ASS I`� ❑ EAGL ON B SE I.- /YD RIM=170.07 IE 4"PVC(SE)=169.57 a ❑ Jn n YD RIM=170.44 IE 4"PVC(W)=1f PATIO N ' PAVER ; Terra B- SAP W SCULPTURE JAR \AE PLE ,JAP NIPPLE WALL 9 — JA MAP S ONE PATH(7YP) - IAAPLE ° �TDNE POND FIN FL=174.8 7]N ..1EXISTING f� HOUSE 9 i DISTANCE TO SOUTH END OF PARCEL BOUNDARY: 64.34' 0 20 40 Feet Site Exploration Plan Geotechnical Engineering Evaluation Proposed Soldier Pile Wall Cannon Residence 29437 10th Ave SW, Federal Way, Washington %Aspect, JUL-2016 AAE/yRMB FIGURE No CONSULTING1503706 RMB�SCC 2 APPENDIX A Soil Boring Logs ASPECT CONSULTING A. Subsurface Exploration Program Geotechnical machine drilled borings B-1 through B-3 and one hand drilled boring, HA- G, were advanced on the Site on February 29, 2016 and March 1, 2016. The machine drilled borings were advanced using hollow -stem auger methods by Boretec Drilling under subcontract to Aspect using a compact track -mounted drill rig and a portable Acker drill rig equipped with a 140-pound cathead hammer. Samples were obtained every 2.5 or 5 feet using the Standard Penetration Test (SPT) in general accordance with ASTM Method D-1586. The SPT method involves driving a 2-inch-outside-diameter split -barrel sampler a distance of 18 inches into the soil with a 140-pound hammer free -falling from a distance of 30 inches. The number of blows for each 6-inch interval is recorded and the number of blows required to drive the sampler the final 12 inches is known as the Standard Penetration Resistance ("N") or blow count. The resistance, or N-value, provides a measure of the relative density of granular soils or the relative consistency of cohesive soils. The hand drilled boring was advanced using hand auger drilling techniques. The exploration was advanced by Aspect field staff using a 2-inch diameter hand auger, advanced at 6-inch intervals. Samples for the hand auger exploration were taken using grab techniques at selected depths. Relatives density was quantitatively assessed with Dynamic Cone Penetrometer Testing (DCPT) at various depth intervals within the hand auger exploration. The DCPT method involves a 15-pound steel mass falling 20 inches to strike an anvil, which drives a 1.5-inch-diameter 45-degree cone into the soil. The number of blows required to drive the cone 1.75 inches is considered one data point. The DCPT data has been calibrated with Standard Penetration Test (SPT) results to provide a more refined estimate of soil relative density and consistency. The locations of explorations are shown on Figure 2 and were estimated in the field by measuring from existing Site features. The machine drilled boring was backfilled with bentonite chips and capped with about 1 foot of excavated soils. The hand drilled boring was backfilled with the excavated soils. PROJECT NO. 150376 • AUGUST 31, 2016 A-1 in 0 0 04 z -0 c m a) 0 0 m w Cl) Cn ca c at U 0 0 z N In M a_ N 0 LO 0 N a, Lf c lL o ; o Well -graded gravel and Terms Describing Relative Density and Consistency �o o a o o GW gravel with sand, little to DensitySPT(2)blows/foot ° ° no fines Very Loose 0 [0 4 Test Symbols 0' ' Coarse- Loose 4 to 10 FC = Fines Content o 0 o o u Poorly -graded gravel Grained Soils Medium Dense 10 to 30 G = Grain Size 0 0 a 0 0 0 0 o GP and gravel with sand, Dense 30 to 50 M = Moisture Content o 0, a little to no fines Very Dense > 50 A = Atterberg Limits li o� Consistency SPT(z)blows/foot C = Consolidation Silty gravel and silty DID = Dry Density ' GM gravel with sand Fine- Very Soft 0 to 2 K = Permeability ° Grained Soils Soft 2 to 4 Str = Shear Strength Medium Stiff 4 to 8 Env = Environmental Clayey gravel and Stiff 8 to 15 PiD = Photoionization Very Stiff 15 to 30 Detector GC clayey gravel with sand Hard >30 LL. �tiC.•� m 0 0 I O N VI ' U o v N O `o z co p0� `1 0 a m c LO LL N 0 NI m T C L rn (aO 2)U = O Well -graded sand and SW sand with gravel, little to no fines Poorly -graded sand Sp and sand with gravel, little to no fines Silty sand and SM silty sand with gravel Clayey sand and SC clayey sand with gravel Silt, sandy silt, gravelly silt, ML silt with sand or gravel Clay of low to medium CL plasticity; silty, sandy, or gravelly clay, lean clay Organic clay or silt of low OL plasticity Elastic silt, clayey silt, silt MH with micaceous or diato- maceous fine sand or silt Clay of high plasticity, CH sandy or gravelly clay, fat clay with sand or gravel Organic clay or silt of OH medium to high plasticity Peat, muck and other PT Ij highly organic soils Component Definitions DesCriptlye Term Size Range and Sieve Number Boulders Larger than 12" Cobbles 3" to 12" Gravel 3" to No. 4 (4.75 mm) Coarse Gravel 3" to 3/4" Fine Gravel 3/4" to No. 4 (4.75 mm) Sand No. 4 (4.75 mm) to No, 200 (0.075 mm) Coarse Sand No. 4 (4.75 mm) to No. 10 (2.00 mm) Medium Sand No. 10 (2.00 mm) to No. 40 (0.425 mm) Fine Sand No. 40 (0.425 mm) to No. 200 (0.075 mm) Silt and Clay Smaller than No. 200 (0.075 mm) (3) Estimated Percentage Moisture Content Percentage Dry - Absence of moisture, by Weight Modifier dusty, dry to the touch <5 Trace Slightly Moist - Perceptible moisture 5 to 15 Slightly (sandy, silty, Moist - Damp but no visible clayey, gravelly) water 15 to 30 Sandy, silty, clayey, Very Moist - Water visible but gravelly) not free draining 30 to 49 Very (sandy, silty, Wet - Visible free water, usually clayey; gravelly) from below water table Symbols Cement grout Blows/6" or surface seal Sampler portion of 6" Type Bentonite 2.0" ODI w Sampler Type chips Split-Spoom Description Grout Sampl u) seal (S"Continuous Push Non -Standard Sampler - Filter pack with blank casing Bulk sam section 3.0" OD Thin -Wall Tube Sampler - Screened casing (including Shelby tube) or Hydrotip with Grab Sam Grouted Transducer filter pack Portion not recovered End cap (1) Percentage by dry weight (5) Combined USCS symbols used for (2) (SPT) Standard Penetration Test fines between 5% and 15% as (ASTM D-1586) estimated in General Accordance (3) In General Accordance with with Standard Practice for Standard Practice for Description Description and Identification of and Identification of Soils (ASTM D-2488) Soils (ASTM D-2488) (4) Depth of groundwater Q ATD = At time of drilling BGS = below ground 1 Static water level (date) surface Classifications of soils in this report are based on visual field and/or laboratory observations, which include density/consistency, moisture condition, grain size, and plasticity estimates and should not be construed to imply field or laboratory testing unless presented herein. Visual -manual and/or laboratory classification methods of ASTM D-2487 and D-2488 were used as an identification guide for the Unified Soil Classification System. A1L PROJECTNO. Aspect Exploration Log Key "" FIGURE NO. CON5ULTING A-1 J Cannon Slo a Stabili-150376 Geotechnical Ex loration Lo1 YCOSEt Fc Project AdUress & Site Specific Location Coordinates (Let, Lon WGS84) ExplorationNumber I N G 29437 10th Ave SE, Federal Way„ Washington. 47,3343,-122.348 (est.) B-1 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) Borelec Trackmounted Cathead; 140 lb hammer, 30" drop 169' operator Exploration Methods) Work SlarUComplefion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Maclen Hollow -stem auger 2/29/2016 NA 17.5' (ATD) Depth Elev. Exploration Completlon Sample Content • water Content (%)! Water Blows/6 Tests MTypeal Description Depth (n) (feet) (feet) and Noes Type/ID FILL Soft, very moist, dark yellow, Bitty CLAY (CH); high - - — - — - - plasticity clay. scattered organics. Ex�lorellan backtiMed - - - - - VA hentonhe chips and capped veih excavated soil. � �, • • 1 MC 2 165 PRE-FRASER NONGLACIAL DEPOSITS _ 5 Stiff, very moist, gray with reddish yellow staining on 5 3 fractures, slightly sandy SILT (ML); low plasticity N N _ 4 non-dilatent silt, occassional fire organics. R Very stiff, very moist to wet, gray with reddish yellow bands, slightly sandy SILT (ML); non -plastic moderately •- - — - - — 6 dilatent silt. frequent fine sand laminations with reddish m U) r 9 GS yelllow staining about every 1-inch. 12 ^ PRE-FRASER GLACIOLACUSTRINE DEPOSITS 10 Very stiff, moist, gray, slightly clayey SILT (ML); -10 7 non -plastic silt, very thinly laminated. V) - - - - - - 9 10 GH FC=99.6% 155 - -- -- 15 Becomes thinly laminated. -15 8 w _0 10 MC 12 Disturbed zone with blocky fracture at 16.2' bgs about 114 to 118 inch -thick perpendicular to core axis. V 2/29/2016 Very stiff, moist to very moist, gray SILT (ML); thinly 150 - - - - - - laminated low -plasticity silt. 20 20 9 N • 11 13 Mc 15 145 r Legend Plastic Llmlt ® No Soil Sample Recovery nt ifl Split Barrel 2" X 1,375" (SPT) F--1 Liqud Limit See Exploration Log Key for SZ Water Level (ATD) explanation of symbols Exploration log B-1 M a � Lagged by: JGF Approved by: HHH Sheet 1 of 3 Cannon Slo a Stabili-150376 Geotechnical Ex loration Lo YT�Ct Project Address & Site Specific Location Coordinates (LatLon WGS84) Exploration Number I N G 29437 10th Ave SE, Federal Way„ Washington. 47.339,-122.348 (est.) B�7 Contractor Equipment Sampling Ground Method Surface (GS) Elev. (NAVD88) Boretec Trackmounted Cathead; 140 lb hammer; 30" drop 169' Dperatr" Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Maclen Hollow -stem auger 2/29/2016 NA 17.5' (ATD) Qcplh (feel) (fElev.tExplo (feet) Completion Sample and Notes Type/ID and Blows/foot • water Content (% ),D Blows/6 Tests Material Type Description Depth (ft) 4 8 1 U) �_ 10 11 Disturbed zone perpendicular to core axis between 26.1' and 26.5' bgs; may be up to 0.4' thick. ----------------------- Hard, wet, gray, sandy SILT (ML); low -plasticity silt, fine 140 — - — - sand, scattered organics, very mucky sample. 30 30 7 — — — 16 MC GS 20 ----------------------- Hard, wet, gray, slightly sandy, slightly clayey SILT 135 - - - - - - (ML); low -plasticity silt, no obvious bedding, scattered organics. 35 35 14 — - 20 29 Hard, wet, gray, slightly sandy, slightly clayey SILT (ML); low -plasticity silt, fine sand. 130 - — 40- 40 0 16 v) 23 40 125 Hard, slightly moist to moist, gray, slightly clayey SILT (ML); very thinly to thinly laminated, 118 inch fracture zone perpendicular to core axis. 45 45 18 m _ _ _ _ 29 50 120 — Legend Plastic Limit Liquid Limit a 01 ® No Soil Sample Recovery 4 Water Level (ATD) See Exploration Log Key for explanation of symbols Split Barrel 2" X 1.375" (SPT) > Exploration log Logged by: JGF B-1 Approved by: HHH Sheet 2 of 3 Slope Stabili-150376 Geotechnical Ex loration Log ���tCannon Coordinates (Lat,Lon WGS84) Exploration Number Project Address & Site Specific Location �" CON 5 u LT I N G 29437 10th Ave SE, Federal Way„ Washington. 47.339,-122.348 (est.) B-1 Contractor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) Boretec Trackmounted Cathead; 140 lb hammer; 30" drop 169' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Maclen Hollow -stem auger 2/29/2016 NA 17.5' (ATD) Depth (feet) Elev. (feet) Exploration Completion and Notes Sample TypeilD Blowsifoot • Water Content (% )* 4 Blowsi6 Tests Material Type Description De lh (ft) N 18 u) - — - - — - - 29 Fracture zones prependicular to core axis 1/8 inch -wide 50 at 50.8' and 51.2' bgs. 115. - -- --- m 14 w --- --- 22 42 50/4 105 65 I 1'00 III 70 95 Legend Plastic Limit t----i Liquid Limit a) _0 ® No Soil Sample Recovery 9- Water Level FATT]) [J Split Barrel 2" X 1.375" (SPT) °? U) Gravelly drilling; No recovery Bottom of exploration at 60.4 ft. bgs. See Exploration Log Key for explanation of symbols Logged by: JGF Approved by: HHH 55 1 60 1 65 1 70 1 Exploration log B-1 Sheet 3 of 3 Cannon Slo a Stabili-150376 Geotechnical Ex !oration Log_ y�RFct Project Address & Site Specific Location Coordinates (LatLon WGS84) Exploration Number I N G 29437 10th Ave SE, Federal Way„ Washington. 47.339,-122.349 (est.)n Contractor Equipment Sampling Method Elev. #L Ground Surface (GS) (NAVD88) Boretec Trackmounted Cathead; 140 lb hammer; 30" drop 160' Dpera!:'r Exploration Method(s) Work StartJCompletion Dates Top of Casing Elev. (NAVDB$) Depth to Water (Below GS) Maclen Hollow -stem auger 2/29/2016 to 3/1/2016 NA 18.5' (ATD) Depth (fElev.t) Exploration Completion Sample Water Content Blowsifoo[ ( • % )41 Blows/6 Tests Material Description (Feet) (feet) and Notes Type/ID Type Depth (ft) DID 2Q_'0 4050 LANDSLIDE DEBRIS Medium stiff, moist, very pale brown and yellowish red - - - - - fracture stains, slightly clayey SILT (ML); non -plastic silt, trace fine sand, laminated. EWEgratipn GBcidllled w bentonhe chips and capped wiN axCavatad spit. -- - 3 • • 3 MC 5 5 155 Stiff, moist, brown and yellowish red fracture stains, clayey SILT (ML); non -plastic silt, occassional clay 5 N 3 laminae, thinly laminated. Co - - 5 MC AL 6 PRE-FRASER NONGLACIAL DEPOSITS Very stiff, very moist, gray and brown with yellowish red - - - - - - - 7 fracture staining, clayey SILT (ML) interbedded with U • 7 GH AL trace sandy SILT (ML)and CLAY (CL); non -plastic silt 10 FC=96.6i and low -plasticity clay, thinly laminated. 10 150 6 Laminations at approximately 45 degrees from core 10 N • 7 MC axis. 10 n Fracture zone perpendicular to core axis with angular - - - - - clay and silt fragments in silt matrix from 11.2' to 11.5' bgs. ------------------------- Very stiff, very moist, brown, sandy SILT (ML); non -plastic silt, fine sand, rare organics, thin laminations inclined approximately 30 degrees from 15 145 core axis. 15 11 U) - - - - 14 GS 14 FC=79.5 n Becomes gray at 16.2' bgs. V2/29/2016 ____________________ PRE-FRASER GLACIOLACUSTRINE DEPOSITS_ - Hard, wet, gray, slightly sandy SILT (ML); low -plasticity, very thinly to thinly laminated silt. 20 140 20 11 U) - --L 15 Mc 17 Legend Plastic Limit Liquid Limit ® No Soil Sample Recovery s In Split Barrel 2" X 1.375" (SPT) > Q7 Water Level (ATE) See Exploration Log Key for explanation of symbols Exploration P log � co 2-Approved Logged by: JGF B-Z by: HHH Sheet 1 of 2 ��CtCannon Slope Stability-150376 Geotechnical Ex loration Log 1 Project Address & Site Specific Location Caordnates (Lat,Lon WGS84) Exploration Number C N 5 U ET I N G 29437 10th Ave SE, Federal Way„ Washington. 47.339,-122.349 (est.) B-2 Contractor Equipment Sampling Method Gt%M Surface fGS) Elev. (NAVD88) Boretec Trackmounted Cathead; 140 lb hammer; 30" drop 160, Operator Expia-afron Melhod(s) Work Stari/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Maclen Hollow -stem auger 2/29/2016 to 3/1/2016 NA 18.5' (ATD) Depth Elev. Exploration Completion Sample Blows/foot • De th (feet) (feet) and Notes TypellD water Content (% )* Alowal6 Tests MTypeel Description (ft) 13 Hard, moist, yellow SILT (ML) interbedded with silty 20 CLAY (CL); 1/8 inch silty clay laminae every 2" to 6", nnc oxidized with re FeO alteration surrounding clay 31 laminae. 130 17 N 19 — -- 21 125 40 120 L 7 u 7 7 i J Il 3 45 115 3 L 3 i 7 7 ,1 trend Plastic Limit Liquid Limit ®No Soil Sample Recovery SZ Water Level (ATD] E : � Split Barrel 2" X 1.375" (SPT) (a a) ?j (1) rn a L L 9 Hard, moist, gray with olive yellow laminations SILT (ML); low plasticity, thinly laminated silt. Becomes light yellow brown at 30.5' bgs. Becomes thickly bedded to massive at 31' bgs. Bottom of exploration at 31.5 ft. bgs. See Exploration Log Key for explanation of symbols Logged by: JGF Approved by: HHH 35 1 40 1 Exploration log B-2 Sheet 2 of 2 Cannon Slope Stability-150376 Geotechnical Ex loration Log �e�i VCO Prnjecr Address d Site Spec& Location Coordinates aat,Lon WGS8d) Exploration Number N S U lT I N G 29437 10th Ave SE, Federal Way„ Washington. 47.339,-122.349 (est.) ��� Contractor Equipment Sampling Method Surface Elev. Ground (GS) (NAVD88) Boretec Trackmounted Cathead; 140 lb hammer; 30" drop 170' operator Exploration Method(s) Work Slarl/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Maclerl Hollow-sterrl auger 2/29/2016 NA 9.5' (ATD) Depth (feet) Elev. Exploration Completion Sample (feet) and Noles Type/ID Blows/foot • Water Content (% )• 131ows/6 Tests Material Type Description Depth (ft) FILL Medium stiff, moist, olive yellow and reddish yellow — — — — - mottled, silty CLAY (CH); high plasticity clay, trace fine to coarse sand, scattered organics. Exploration hncWed - — - — - with bentonlle chips and capped vfih Cxcavaled sail. — -- 3 '� • 3 2 MC AL PRE-FRASER NONGLACIAL DEPOSITS 5 165 Stiff, moist, brown and reddish yellow mottled, clayey 5 N 3 SILT (ML); non -plastic silt, fine sand, scattered - - — - - 5 MC AL organics and root casts. 8 Very stiff, moist, gray, sandy SILT (ML); non -plastic slightly cohesive silt, fine sand, scattered organics. — — — 9 10 GS 13 FC=60,5i s7 z/zs/zots 10 780 10 7 N • 8 GS — 9 FC=73.4 PRE-FRASER GLACIOLACUSTRINE DEPOSITS Very stiff, very moist, gray, slightly clayey SILT (ML); 15 155 low -plasticity silt, scattered clayey laminae. -15 8 Co —•_ 11 MC 14 Fracture perpendicular to core axis at 16' bgs. 20 150 20 8 N • - - 11 MC 14 Hard, very moist, gray, SILT (ML); low -plasticity silt with ji slight dilatency, trace sand. Legend Plastic Limit F----i Liquid Limit ® No Soil Sample Recovery 2 Water Level (ATl7) See Exploration Log Key for E to. [) Split Barrel 2" X 1,375" (SPIT) explanation of symbols Exploration P log _j ICU°1 Logged by: JGF B-3 Approved by: HHH Sheet 1 of 2 Cannon Slope Stability-150376 Geotechnical Ex loration Lo pent Vs Project Address & Site Specific Location Coordinates (Lof.ton WGS84] Exploration Number ONSULT I N G 29437 10th Ave SE, Federal Way„ Washington. 47.339,-122.349 (est.) Ground Surface (GS) Elev. (NAVD88) op-3 Contractor Equipment Sampling Method Boretec Trackmounted Cathead; 140 lb hammer; 30" drop 170' Operator Exploration Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Maclen Hollow -stem auger 2/29/2016 NA 9.5' (ATD) Depth (feet) Elev. (feet) Exploration Completion and Notes Sample T, e/ID Blows/font Water Content (% )� 1 4 Blows/6 Tests Material Type Description II Depth p (ft) 13 N 14 Fc — — — — — 17 FC=98.1 % 1 30-t140 12 m 18 FC — _ 22 FC=81.2 % 1 35-+135 404130 1 I_.1-1__I-I 51 451125 Legend Plastic Limit F ----i Liquid Limit i92 No Soil Sample Recovery SZ Water Level (ATD) a LO in Split Barrel 2" X 1.375" (SPT)? fn L 1 C ----------------------- Hard, wet, gray and olive yellow banded, sandy SILT (MIL); low -plasticity silt, fine sand, laminations inclined around 30 degrees from the core axis.. Bottom of exploration at 31.5 ft. bgs. See Exploration Log Key for explanation of symbols Logged by: JGF Approved by: HHH 30 1 35 1 40 1 45 1 Exploration log B-3 Sheet 2 of 2 VC R�ct Cannon Slope Stability-150376 Geotechnical Ex loration Low Project Address & Site Specific Location Coordinates (Lat,Lon WGS84) Explora fort Number O I N G 29437 10th Ave SE, Federal Way„ Washington. 47.339,-122.349 (est.) HA-1 Contrwor Equipment Sampling Method Ground Surface (GS) Elev. (NAVD88) Boretec Trackmounted Cathead; 140 lb hammer; 30" drop 140' operator Expioratton Method(s) Work Start/Completion Dates Top of Casing Elev. (NAVD88) Depth to Water (Below GS) Maclen Hollow -stem auger 2/29/2016 NA 3.8' (ATD) Blows/foot • Depth Elev. Exploration Completion Sample Wet Content (% )A R1owGl6 Tests Material Description Depth (feet) (feet) and Notes Type/ID 5 Type (ft) COLLUVIUM Soft, very moist, gray, brown and yellowish red, slightly - - - - - sandy, slightly clayey SILT (ML); low to moderate plasticity silt, fine sand, scattered organics (twigs), occassional charcoal fragments. Exploation backritlad — — — with excavated loll. y V 2/29/2016 LANDSLIDE DEPOSITS 5 135 N Stiff, very moist to wet, gray and yellowish red mottled, 5 slightly sandy SILT (ML); low -plasticity silt, trace coarse sand, occassional charcoal fragments. Bottom of exploration at 6 ft. bgs. 1107t30 NI 151125 20 Ili IIIIIII u Legend Plastic Limit Liquid Limft a) _0 Grab Sample $z Water Level (ATD) `m> E � � ai to J See Exploration Log Key for explanation of symbols Logged by: JGF Approved by: HHH =I 20 1 Exploration log HA-1 Sheet 1 of 1 APPENDIX B Laboratory Testing Results ASPECT CONSULTING B. Geotechnical Laboratory Testing Laboratory tests were conducted on selected soil samples to characterize certain engineering (physical) properties of the soils at the Site. Laboratory testing included determination of grain -size distribution, moisture content, and plasticity. The laboratory tests were conducted in general accordance with appropriate ASTM test methods. Test procedures are discussed below. The grain -size distribution of selected samples was analyzed in general accordance with ASTM D422, Standard Test Method for Particle -Size Analysis of Soils without hydrometer determination of fines content. The moisture content of selected samples was analyzed in general accordance with ASTM D2216, Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass. The liquid limit, plastic limit, and plasticity index of selected samples were analyzed in general accordance with ASTM D 4318-10, Standard Test Methods for Liquid Limit, Plastic Limit, and Plasticity Index of Soil g-1 PROJECT NO. 150376 • AUGUST 31, 2016 07 tG W CO CO b7 b0 Cd �., CO !xJ CO lA tz w i0 O O G G O O O C O D O O T3 N N J N T N N N N A N O N N N N A N W N G N OAo LA �c J cA ON+ tz bC CA to by MMMMMFVVW 4+ w w EN W W v cncnC4"I cnC4C4c4cnCo lii w N N �— N U O D U a a o 0 0 0 o c� o o ►• c o �L J O V�i N OC W G 41 Q` N LA N U'+ V� OG •. Q. .- W N O to O` N �c CD C O NC C N .J-. LA or a A OG 00 JO A �-• 00 OR N J N W O �c O U + 00 N N - C~ _ J J W VA W G A W W O W n` C W G OC w J 0 00 � 0 0 W 0 N a, J w J N 00 OG �D U O W 1O LAN J oa O O N O OC IO O 0 0o N O A �O �O N N N NO W O, C to A W G U t�CD CD a cr �e R a �cn c N a w w r U V n �T W N C W a o°o LACD N 07 O C C tA to + �e x CD CD w oc W w G G+ a Q� w J O .y 0 y a Ic 0 o N 0 V, o � O 0 y m 3 y G d Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Hydrometer Report Project: Cannon S1npe Slabllily Date Received: II-Mar-16 AST NI D 2487 Soils Classification Project #: 16BO13-03 Sampled By: Client ML. Silt Client : Aspect Consulting Date Tested: 14-Mar-16 Sample Color Source: B-1 S4 @ 10' Tested By: M. Blodgett-C gray Sam leU: B16-0229 ASTM D422, I1)'DRO�IGTCR ANAI.1 SIS ASTNI C436 Assumed Sp Gr : 2.70 Sieve Analysis Sample Weight: 50.35 grams Grain Size Distribution Hydroscopic Moist.: 10.11 % Sieve Percent Soils Particle Adj. Sample Wgt: 45,73 grams ACCREQITSQ1 Size Passing Diameter ,r,,,,,,,,,,,,,,,„,,,,,,,,e, 3,0 100% 75.000 mm Hydrometer 20" 100% 50.000 mm Reading Corrected Percent Soils Particle 15' 100% m 37.500 m Minutes Reading Passing Diameter 1 25" 100% 31.500 mm 2 41 88 8% 00294 mm 1.0" 100% 25.000 mm 5 31 671% 0.0201 mm 3/4" 100% 19.000 mm 15 16 34 6% 0.0128 mm 5/8" 100% 16.000 mm 30 12 26.0% 0.0093 mm 1/2" 100% 12.500 mm 60 7 15.2% 0.0068 mm 3/8" 100% 9 500 mm 250 2 43% 0.0034 mm 1/4" 100% 6.300 mm 1440 1 2.2% 0.0014 mm #4 100% 4.750 mm 910 100% 2.000 mm % Gravel: 0 0% Liquid Limit: 0.0 % #20 100% 0.850 mm % Sand: 0 4% Plastic Limit: 0.0 % #40 100% 0.425 mm % Silt: 90.1% Plasticity Index: 0 0 % #100 100% 0.150 mm % Clay: 9..5% #200 99.6% 0 075 mm Silts 99.4% 0 074 mm 93.7% 0.050 mm 66.6% Q020 mm Clays 9.5% 0.005 mm 2.8% 0 002 mm Colloids 1.5% 0.001 mm iiSDA Soil Textural (1aSSiGtation Particle Size %Sand: 20-005mm % Silt: 0,05 - 0,002 mm % Clay: < 0,002 mm USDA Soil Textural Classification Silt All malts apply only to eeluel loeedans end memrials ksled Asa mumel pmlectian to cgrnt4 the public and eurseheA ell repods ere submind a: the conCdenuel PmGcrN ofegrnts end euNar'vaGon far pubhcefion afsmlemrnts, conclusions "r eArvets fmm or regarding our rtportz is—d pending --i— ep,—d Comments: Reviewed by:�L�` Corporate — 777 Chrysler Drive a Burlington, WA 98233 a Phone (360) 755-1990 a Fax (360) 755-1980 Regional Offices: Olympia — 360.534.9777 Bellingham — 360.647.6111 Silverdale -- 360.698.6787 Tukwila -- 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Sieve Report L FProject: Cannon Slope Stability Date Received: 11-Mar-16 AST%I D-2487 Unified Soils Classification System rojectN:16B013-03 Sampled By: Client %I L. Silt with Sand Client: Aspect Consulting Date Tested: 14-Mar-16 Sample Color: 7<EQ� 77m Source: B-1 S-8 @ 30' Tested By: M Blodgett -Carrillo pray . Sam leis: 81"232 AST14 11-22ICAMi D-24M ASVM D-43IS. ASTM D-5821 Dµt= 0.005 nms 96 Gravel - 0.0% COefT OrCYrralYra, Cc a 1.50 Specifications DtF01= O.010 may % Send = 25.9% Coefl: of Uniformity, Cu = 6.00 No Specs Dri3F= O.015 rrm % Silt & Clay= 74.1 % Fineness Modulus= Q39 Sample Meets Specs ? N/A Dr30i= Q030 mm Liquid Limit = Q0% Plastic Limit = QO% Dr,O,= Q051 mm Plasticikv Index= QO% Moisture %, as sampled= 37.1% Dr.i= 0.061 mm Send Equivalent = n/a Req'd Send Equivalent = 13,= 0.394 nim Fracture %. 1 Face= n/a Req'd Fracture %. l Face= tlu:l nano- 51'n Fracture %, 2+Faces=111A AFranute °..2+Faces = ASTAI C-136„LS TAI D•6913 - �flYnl [nlel'polalC4 Gmin Site DislribNion Cumulative Percent Pmaln Cumuhthv Percent PAS31ntf Sieve L'S Size Mehra Specs Mas Specs Min E 2,00" 30D.PD 100% 100.0% u r1?; 10001, 250,00 100% 100.0% 00% 8001, 20000 100% lK0% 0,0¢/0 6 00" 150.00 100% 1000% 0.0% 400" 100.00 100% 10010% 0.0% • 3 00" 75.00 100% 100.0% 00% 2 50 63,00 100% 100.0% 0 0% L I 200 5000 100% 100.0% 00% rOx 70 ox 1 75" 45.00 100% 100.0% 00% 150 1, 25" 1.00" 37,50 31.50 25.00 100% 100% ]00% 100.0% 100.0% 100.0% 00% 00% 00% € 3/4" 19.00 100% 1100,0% 0.0% 5/8" 16.00 ]00% 100,0% 0.0% x 1/2" 12-50 ]00% 100.0% 00% 3/8" 9.50 100% 100.0% 0.0% mx 1/4" 6.30 100% 100,0% 0.0% #4 4.75 100% 100.0% 0.0% max #8 2.36 100% 100.0% QO% �x 410 2.00 98% 98% 100.0% 0.0% 416 1.18 94% 100.0% 0.0% mx pox #20 0.850 92% 10Q0% 0.0% 430 0 600 91 % 100.0% 0.0% #40 0.425 90% 90% 100.0% 0.0% + 01' LEJ 450 0.300 89% 100.0% 0.0% 460 0.250 8B% 100.0% 0.0% mo urm v06 br-o 480 0180 87% 1000% 0.0% w 000i� 4100 0.150 87% 87% 1000% 00% 4140 0106 79% 1000% 00% vaueesre rmmt 4170 0 090 77% 1000% 00% 9200 0075 74% 74% 1000% 00% sM s¢� -• - Ym tom -" -Min -.� s.....n.+ Cp 'JY p F-.-a 5- .ssI Iv1 Comments: Reviewed by: Corporate - 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia - 360 534.9777 Bellingham -- 360.647.6111 Silverdale -- 360.698.6787 Tukwila -- 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering - Special Inspections - Materials Testing - Environmental Consulting ASTM D4318 - Liquid Limit, Plastic Limit and Plasticity Index of Soils Project: Cannon Slope Stability Date Received: 11-Mar-16 JIVisusil Identification ProjectN: 16BO13-03 Sampled By: Client iitWith clay Client: Aspect Consulting Date Tested: 14-Mar-16 SampleCalor Source: B-2 S-5 @ 5' Tested By: M. Blodgett -Carrillo rowrl SampleN: B16-0235 Wei0l of Wrt Sol if + Pan: Weight of MY Soils + Paw woizhi or Pan: Wright or bty Soi h: ►►•agbt ornloi;:iirt: 9G Nfaistore: Kuhl ber of Blows: WOZI,I or► o sails +pan: %1"d ltt 4f pry Sails+PIG: %velchI of pan: W601 of Dry Soils: WeiFM of N1 oisNrt: %Moisture: i.ig,iid Limit Determination al -2 43 PIuslie Limit Determination Iff 02 k3 Plasticity Chart 1A NS ar, Liquid Limit @ 25 Blows: N/A Plastic Lim it: N/A Plasticity Index, Ip: N/A 94 95 96 ACCRED1TED1 80.0'h 70.0 % ao.o "U' Line � 50.0 rh � •-. _ Chi or OH MH or pH C CL•ML a.o x 10.0% 20.0%. 30-0% 40.0% 50.0.'h 60JOx. 70.01% 60.0% ao.0% tau-0% 11e-0% Liquid Limit Liquid Limit 100 % s0 % 80% 70 % 60% f e 50% 40 % 30% 20% 10% 0% 10 Number of Blows, "N" 100 11 CW,TioM Spran Engineering$ Te h irul S—i—PS 1996-98 NI reruer �pl�il aid o u� euJ niaicneir re4o5 A� f mur�� prixr orn io elmo. .ue puhlrc wid wnrrlrn, ali errnr.ure r.Fm.nw[ as tic a 1j&-u M, ly a — W-t cut .-1- wr A'r::esriin ejej ri�remmru�mrluum p�— ..—d 6om or regarding our reportskre-d pending approval Comments: AS received moisture =30-8% Slow dilatancv and inability to roll down to 1 /8" the sample has been determined to be non -plastic. Reviewed by: Corporate — 777 Chrysler Drive - Burlington, WA 98233 - Phone (360) 755-1990 - Fax (360) 755-1980 Regional Offices: Olympia — 360.534.9777 Bellingham — 360.647.6111 Silverdale — 360.698-6787 Tukwila — 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc.` Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Hydrometer Report Project: Cannon Slapc Stability Date Rcceivcd: 11-Mar-16 S-I M 1) 2387 Suils C:lacsification Project#: 16BO13-03 Sampled By: Client W., Silt Client: Aspect Consulting Date Tested: 14-Mar-16 Sam plc Color Source: B-2 S-3 @ 7.5' Tested By: M. Blodgett-C brown Sam Ic:t: B16-0236 AST•�I D--l22, 11Y0IZOMETER ANALYSIS 15T1I C-136 Assumed Sp Gr : 2.70 Sieve Analysis Sample Weight: 5043 grams Grain Size Distribution Hydroscopic Moist.: 10 03% "qA= Sieve Percent Soils Particle Adj. Sample Wgt: 45 83 grams Size Passing Diameter 3.0" 100% 75.000 mm Hydrometer 2.0" 100% 50.000 mm Reading Corrected Percent Soils Particle 1.5" 100% 37 500 mm Minutes Reading Passing Diameter 1,25" 100% 31.500 mm 2 36 773% 00306 mm 1.0" 100% 25.000 mm 5 30 64.4% 0.0203 mm 3/4" 100% 19.000 mm 15 19 40.8% 0.0126 mm 5/8" 100% 16.000 mm 30 15 32.2% 00091 mm 1/2" 100% 12.500 mm 60 10 21.5% 00067 mm 3/8" 100% 9,500 mm 250 4 8.6% 00034 mm 1/4" 100% 6.300 mm 1440 2 4.3% 00014 mm 94 100% 4.750 mm 910 99% 2.000 mm % Gravel: 0.0% Liquid Limit: 0 0 % #20 99% 0,850 mm % Sand: 1.4% Plastic Limit: 0 0 % 940 99% Q425 mm % Silt: 83 6% Plasticity Index: 0.0 % #100 99% Q 150 mm %Clay: 150% #200 98.6% 0,075 mm Silts 98.1% 0074 mm 86.6% 0.050 mm 63,5% 0.020 mm Clays 15.0% 0.005 mm 5 6% 0 002 mm Colloids 3.0% 0001 mm USDA Soil Te[tund Classification Particle Size % Sand: 2.0 - 0.05 mm % Silt: 0.05 - 0,002 mm %Clay: <0,002 mm USDA Soil Textural Classification Silt All insults apply wly to eclud locelions end memdels tcstd AsemmuelpmlaY"n to cbcnLC lbe public end ourulvc;ell¢puns art submincdaz utc confidcnud p,operry ofcGcncc and euawmnfion for WbGcaGon ofsvmmcnt; cancluv"ns "re lack Gum ar rtgud'vig our n:ports is mxrvd p ding cur wd.. eppmvel Comments: Reviewed by: Corporate — 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia -- 360.534.9777 Bellingham - 360.647.6111 Silverdale — 360.698.6787 Tukwila — 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspections • Materials Testing • Environmental Consulting ASTM D4318 - Liquid Limit, Plastic Limit and Plasticity Index of Soils Project: Cannon Slope Stability Project #: 16BO13-03 Client: Aspect Consulting Source: B-2 S-3 @ 7 5' Sam Plc#: B16-0236 Date Received: 11-Mar-16 Sampled By: Client Date Tested: 14-Mar-16 Tested By: M Blodgett -Carrillo ieusl Identification Or with clay ple Color Z.i nid Limil 13emrminalinn 41 42 43 rla t 04 Weight of Wet Soils +Pan: Weight of Dry Soils+Pan: Weight of Pan: Weight of Dry Soils: Liquid Limit @ 25 Blows: N/A Weight of Moisture: Plastic Limit: N/A %Moisture: Plasticity Index, Ip: N/A Plastic Limit Determination at A =3 ..-. 45 #6 Weight or Wet Soils + Pan: Weight of Dry Soils + Pan: Weight of Pan: Weight of Dry Soils: Weight of Moisture: II ACCREDITFE) % Moisture: Plasticity Chart e0.0 % 70.0 % 60.0 % "U' Line _ x "A" ilk v 50.0 % c 40.0 % CH or OH 'u - 30.0 % a ' MH or OH zo.o % � � CL or0 10.0 % L-ML 0.0 % 0-0 % 10.0 % 20.0 % 30.0 % 40.0 % 50.0 % 60.0 % 70 0 % 60 0 % 90.0 % 100.0 % 110.0 % Liquid Limit K Cep.,'N S.— Lap--' R rea.6wia1 Sn—. ]' . kgM A`ewli fi i0—i 1 A—. M�xa �o. Md�r,�ti t p.atK.,:rt—��.re.'�Srryn.i:;K•i:,6ii,'i ntrensfrom or regarding our reports isroscrvad pcndingwrxriurn opp,o�d T Comments: Rapid dilatancv and inability to roll down 1 /S"- sample has been determined to be non -plastic } Reviewed by: Corporate — 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia— 360.534.9777 Bellingham — 360.647.6111 Silverdale — 360.698.6787 Tukwila — 206.241.1974 Visit our website: www.mtc-inc.net MTC Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting6r..ic.+N�� Sieve Report Project: Cannon Slope Stability Date Received: 11-Mar-16 aSD�f D-2487 Unified Soils Classification System ICIM Project N: 16BO13-03 Sampled By: Client ML. Silt with Sand Client: Aspect Consulting Date Tested: 14-Mar-16 Snmpty Color: ACCFtEp1TEO Source: B-2 S-5 @ 15' Tested By: M. Blodgett -Carrillo brouTt ..... ^• W 'ws'• Y y Sam Iem: B16-0238 ASTM DIM. ASTAI Df 2419, ASTM 11-4313. ASTM D-5821 D,,,=0.003 mm °il Gn''q 0.4 w,e CDC Ir of Curral urc, C, = 1.50 Specifications DII°I= 0.009 mm % Sand = 20 5% Coefr of Uniformity, Co = 6.00 No Specs DI„ 1= 0.014 mm % Silt & Clay = 79.5 % Fineness Modulus = 0,02 Sample Meets Specs ? N/A Dls°I= 0.028 mm Liquid Limit = 0.0% Plaslic Limit = 0.0% Dt,°I= 0.047 mm Plasticity Inde = 0.0% Moisture %, as sampled = 27.5 % DI6°I= 0,057 mm Sand Equivalent = n/a Req'd Sand Equivalent = D,,= 0.115 mm Fracture %. 1 Face = n/a Req'd Fracture %, 1 Face = Dust Ratio = 79/99 Fratiute . 2•� Faces = r9a Rccfd Fracture %. 2+ Faces = AST11 C-13& AM-D-031 '7ctuai Interpolated Grain S¢e D1ctdbW1.n Cumulativt Percent Passin Cumutative Percent Pns3W bbb�hf.iezxa 4 >, EaIt111> � L Sieve us Size Metric S ecs P Max S ecs P Min 12W 300.ou IM% toM1A 00% 7M 111111I 10001, 8001, 25000 20000 100% 100% 100.0% 100.0% 0.0% 00% sox 6 00" 150.00 100% 100.0% 00% 4.00" 10000 100% 100.0% 00% ww 3.00" 75.00 100% 100.0% 00% 2.50" 6300 100% 100.0% 00% f zoo" 50.00 100% 100.0% 00% TOK mor 1, 75" 45.00 100% 100,0% 00°/a 1.50" 37.50 100% 100.0% 0.0% 1.25" 31.50 100% 100. 0% 0.0% wx 1, 00" 3A 25, 00 19.00 100% 100% 100.0% 1000% 00% 0.0% x $ 5/8" 16.00 100% 100.0% 00% 1/2" 12.50 100% 100.0% 00% JIIIIII 3/8" 9-50 100% 100.0% 00% a°x 1/4" 6.30 100% 100.0% 00% k4 4.75 100% 100.0% 00% pn 48 2.36 100% 100.0% 0.0% 30v' #10 2.00 100% 100% 100,0% 0.0% #16 1.19 100% 100.0% 00% mw xn 420 0,850 100% 100.0% 0.0% 430 0,600 100% 100.0% 00% #40 0.425 100% 100% 100-0% 0.0% + 1p0M 450 0.300 99% 100.0°/a 00% 460 0.250 99% 100.0% 00% +m w zta° a 611b 480 0.180 99% 100.0% 00% � Co° N10o 0.150 99% 99% 100.0% 0.0% #140 0.106 88% 100-0% 00% awe`s:`Imml 9170 0 090 83% 100 0% 0.0% 4200 0 075 79% 79% 100 0% 00% �. _ -. - Maz 5P. -. -Min lyax �.rtdr 'ga.rNweew Ri.Aw>t'.mmll. ISP[-�A .. .... _ ...._.........-...-...�.._._-......-.......i......n.....r�...a..�i.�.....:..na-.,...�.,ar-.n rcrc.....�,.cs rv+�•r ..i... rrp � Comments: Reviewed by: Corporate -- 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia - 360.534.9777 Bellingham - 360.647.6111 Silverdale -- 360.698.6787 Tukwila - 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspections • Materials Testing • Environmental Consulting MTC �.s resin s ['o-- ASTM D4318 - Liquid Limit, Plastic Limit and Plasticity Index of Soils Project: Cannon Slope Stability Date Received: 11-Mar-16 Visual Identification Project N: 16BO13-03 Sampled By: Client lay with silt Client: Aspect Consulting Date Tested: 14-Mar-16 'ample Color Source: B-3 S-1 @ 2.5' Tested By: M. Blodgett -Carrillo y SampleN: B16-0241 Liquid Limit Determination ki 42 43 94 .',G W, Weight of Wet Sails + pan; 35.14 33,76 3428 WcighI or Pry Sans + Pan: 32.75 31.80 3222 Weight or Pan. 28.13 28.I6 28.$3 Weigh i of Dry Soils: 4.62 164 3.69 Liquid Lim it@25 Blows: 55.6 ►Veigh1 af11o19nrslt 2.39 1.96 2_06 Plastic Lim it: 27,4% % Moisture: 51.7 % $3.9 % 59.8 % Plasticity Index, 1p: 28.2 Niniibrrorslom: 28 36 25 M"eivilOf►5'rl Solis +Pnn: 33.14 31.7.5 weigh! or Dry So41s + Pan: 31.0 31.02 Wright of r.n: 28.14 am ►veiglttorDry 5nih-. 3.14 3.67 ACCREDITED Weight of hlgisrure: 0.86 0.73 �. .... , ,,, ,,.. %nTaisturn: 27.4% 27.1?l. Plasticity Chart 60k % f . 70.0 5i SOD % ` "ll" Line } 40.0% CH or OH R 3t1.0 % . . a � � _ ' iJ1H or OH zD.D % C1. or as L-ML "% 0-0 % 10.01% 20.0 % 30.0 % 40.0 % 50,0 % 60.0 % 70.0 % 80.0 % ti0.0 % 10D'0 % 110.0 % Liquid Limit Liquid Limit 60% 50% a 40% f . 30 20% 10% 0% t0 Number of Blows, "N" 100 aRv1 m . nun irot . W O-N rk V-00cen6uihc11- Nl rtp-,.ic r�6,mnef .. rliccm isdmi,.l �,,,gei,. ��.:i.ni. cy�.o�hNiraa,� �h wrS�ai,�, N,i�.aene. wwuuui, or, czlmcls from or repnrding wr r' puns is rcun•cd pcndin6- x itrn epp.... I Comments: As received moisture content =440% Reviewed by: Corporate - 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia - 360.534.9777 Bellingham - 360.647.6111 Silverdale - 360.698.6787 Tukwila - 206,241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspections • Materials Testing • Environmental Consulting 01 PEll r ASTM D4318 - Liquid Limit, Plastic Limit and Plasticity Index of Soils Project: Cannon Slope Stability Date Received: 11-Mar-16 Visual Identification Project N: 16BO13-03 Sampled By: Client Silt with clay Client: Aspect Consulting Date Tested: 14-Mar-16 Samplc Color Source: B-3 S-2 @ 5' Tested By: M. Blodgett -Carrillo I bro"'n ;Sam pie N: 1316-0242 I-i uid Limit Determination Nl - .0 44 45 96 - weight of wet Soils+Pan: Weight of Dry Soils + Pan: Weight of Pan: Weight of Dry Soils: Liquid Limit @ 25 Blows: N/A Weight of Moisture: Plastic Limit: N/A %Moisture: Plasticity Index, Ip: N/A X: i no he r of 131 uws: Plastir Limit Determination N1 42 03N4 45 N6 Weight orwet Soils + Pan: Weight of Dry Soils + Pan: Weight of Pan: Weight of Dry Soils: ACCRE1dEiED] Weight of Moisture: ce.sar. nuas. raaw a rrµa Plasticity Chart eo o % r� 70.0 60.0 % 'V Line "A" e x 0 50-0 % 40.0 % CH or OH 30.0 % IL ' MH or OH 20.0 % 6L tx o 10.0% 00% 0.0 % 10.0 % 20.0 % 30 0 % 40 0 % 50 0 % 60 0 % 70 0 % 80.0 % s0.0 % 100.0 % 110.0 % Liquid Limit C'�:rpa sEt'+�ryorcrviaR T.xhi—I<<nr.c. PS199Gsi mr.ca ����r.,.0 M.:, i:" r~sir— cr-1 fromor rcpwdin p our r,pon,kr—rvedp,,dlnpourwnitcnopp— Comments: As received moisture content =400% Slow dilatancy and inability to roll down to 1/8" the sample has been determined to be non- lastic Reviewed by: Corporate -- 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia -- 360.534.9777 Bellingham — 360.647.6111 Silverdale — 360.698.6787 Tukwila — 206,241.1974 Visit our website: www-mte-ine.net Materials Testing & Consulting, Inc. ,tYC Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Sieve Report Project: Cannon Slope Stability Date Received: 11-Mar-]6 ASTNI D-2487 Unified Soils Classification System Project #:16B013-03 Sampled By: Client MLSilt withSand Client: Aspect Consulting Date Tested: 14-Mar-16 Sample Color: Source: B-3 S-3 @ 7_5 Tested By: M. Blodgett -Carrillo ya}• ACCREIDiTEO� Sam ko: B16.0243 .�,._, •.,.• „�__.,..,, ASTA1 D-2116, ASTM D-1419 ASThI D-4318.ASE'hl D-5821 DI<i= 0.005 mm % Gravel = QO% Coefr. of Curvature. Cc = 1 50 Specifications Dlial= Q009 mm % Sand = 19,5% Coen. of Unifomtiq. Cu= 600 No Specs DI„ I= 0,014 mm % Silt d Clay = 80.5% Fineness Modulus = 0.08 Sample Meets Specs ? N/A Dlsoi= 0,028 mm Liquid Limil = QO% Plaslic Limit = 0.0% Disoi= 0.047 mm Plasticity Index = QO% Moisture %, as sampled = 24.6% Dual= 0.056 mm Sand Equivalent = n/a Req'd Sand Equivalent = Dial= 0.122 mm Fracture %. I Face = n/a Req'd Fracture %, 1 Face = Dust Ratio = 30/37 Fracture %. 2+ Faces = n/a Req'd Fracture %. 2+ Faces = ASTM C-136, ASTM D-6913 Actual Interpolated Gain Si. DislnbNion Cumulative Percent PassinZ Cumulative Percent Passing ,o s a - F § aax Skye Size Uic Spas MXX Space Alin 12.00" 300.00 100% 100.0% 0.0% 10.00" 250,00 100% 100.0% 0.0% 800" 200,00 100% 100,0% 0,0% 5° wou 6 00�� 150,00 100% 100,0% 0.0% 400" 100.00 100% ]00.0% 0,0% 3 00" 75,00 100% ]00.0% 0.0% eox � 2,50 63.00 100% 100.0% 0,0% 2'00" 50.00 100% 100,0% QO% icx J J70M UP 4100 100% 100.0% QO% 1,50" 37.50 100% 100,0% QO% I 1,25" 31,50 100% 100.0% 0.0% wx mox 1.00" 314" 25,00 19.00 100% 100% 100.0% IORO% 0,0% 00% 9 wx e a 5/8" 16.00 100% 100,0% 0.0% 1/2" 12.50 100% 100.0% QO% 3/8" 9.50 100% ]ORO% RO% as mox 1/4" 6,30 100% 100.0% a0% 44 4.75 100% 10QO% 0.0% 48 2,36 100% 100.0% 0.0% 30 300°* 410 2,00 100% 100% 100.0% Q0% #16 1.18 100% 100.0% 0.0% mx #20 0.850 99% 100,0% 0.0% � #30 0,600 99% 100.0% 0.0% 440 0,425 99% 99% 100.0% QO% +a mox #50 0-300 98% 100.0% QO% #60 0250 97% 100.0% 0.0% 080 QI80 96% 100.0% 0.0% °Y owoox ,po un , amo oa+o #100 0.150 96% 96% 100.0% 0.0% #140 0.106 87% 100.0% 0.0% P°"itle9Ee lmml #170 0.090 84% 100.0% 0.0% 0200 0.075 81 % 81 % 100,0 % 0.0% s,e a s�� r., •sooR Ene�Wo,pmr �i_i_m ivs5-se Comments: Reviewed by: Corporate - 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia -- 360.534.9777 Bellingham - 360.647.6111 Silverdale - 360.698.6787 Tukwila - 206241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting Sieve Report Project: Cannon Slope Stability Date Received: 11-Mar-16 Project #:16BO13-03 Sampled By: Client ASt11 D-2487 Unified Soils Classification System M L, Silt with Sand Client: Aspect Consulting Date Tested: 14-Mar-16 Sample Color: ACCR£dkTEl7 Source: B-3 S-4 @ 10' Tested By: M Blodgett -Carrillo gray e.. M Sam ie#: T316-11244 ASTA3 D-2216, ASTIt D-2419, ASTM D-4318, AST51 0-5821 D„,- 0-005 mm as Qroref = 0.0% Coa1L ofUWA-lum, cr = 1,50 Specifications Drror= 0-010 mm % Sand = 26.6% Coefr. of Uniforrnity, Cu = 6.00 No Specs Drv,,= 0 015 mm % Sill & Clay= 73.4% Fineness Modulus = 0,04 Sample Meets Specs ? N/A Dvaov= 0.031 mm Liquid Limit = 0,0% Plastic Limit = 0.0% Dr,av= 0-051 nun Plasticity Index = 0.0% Moisture %, as sampled = 30 0% Dr.v= 0.061 mm Sand Equivalent = n/a Req'd Sand Equivalent = D,)= 0.126 nun Fracture %, 1 Face= n/a Req'd Fracture %, 1 Face= Dust Ratio= 64M7 FracEwc 95. 2+Faces =n/a ASTM.C-136.-j S 1S:D..,69k3 Actual tnlerpolattri o,si" Size DwInbu4"n Cumulative Percent Cumulative Percent Y slew sin S m Specs vs Mark P-1int ft"4W Max Min wzb 00 ow ]2.00" 300,00 100% I0D-117f. 0.095 10-00" 250.00 100% 100-0% 00% 8.00" 200. 00 100% 100 0% 0.0% sow 80 6 00" 150.00 100% 100-0% 0-0% 400" 100.00 100% 100-0% 0.0% wry 3 00" 7500 100% 100 0% 0-0% 2 50" 63-00 100% 100 0% 00% 2.00" 50.00 100% 100.0% 00% vow Alft 1.75" 45.00 100% 100 0% 00% 1.50 37.50 100% 100.0% 00% rovr 1.25" 31.50 100% 100-0% 0.0% sox 1.00" 25.00 100% 100.0% 0.0% a 3/4" 19.00 100% 100.0% 0.0% �vr. mow 5/8" 16.00 100% ] 00 0% 0.0 1/2" 1250 100% 100 0% 0.0% 3/8" 9.50 100% 100 0% 00% aow na► l/4" 6.30 100% 1000% 0.0% 44 4.75 100% 100,0% 0.0% mn #8 2.36 100% 100.0% 00% avx 410 2.00 100% 100% 100.0% 0.0% #16 1.18 100% 100.0% 0.0% mw xn #20 0 850 100% 100.0% 00% 430 0 600 100% 100 0% 0 0% #40 0425 100% 100% 100.0% 0.0% vo 100� 450 0,300 99% 100.0% 00% 460 0 250 98% 100.0% 0.0% am tm ucm v am On 480 0-180 98% 100,0% 00% n am, #100 0-150 98% 98% 1GO. 01% 0.0% 4140 0106 83% 100.0% 00% a"meesz`tmmr #170 0090 78% 100.0% 00% 4200 0 075 73% 73% 100.O% 00 c..vti-1w.ii.rn lw twfW:k.e �.�s�.....:•.r...nx,�urr,e RY�iwr`n.,.o-r.�:Ur.wwraa ,n•...: ..e. ..�. �.. �e..i �.-.��ninwb taa� .�...•n.f�5i"�..aa vevn�.•n[errci.a +Y rr�ss...�.n.e e.,wuNarylrvs�!�i Comments: Reviewed by: Corporate - 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia -- 360.534.9777 Bellingham - 360.647.6111 Silverdale - 360.698.6787 Tukwila - 206.241.1974 Visit our website: www.mtc-inc.net Materials Testing & Consulting, Inc. Geotechnical Engineering • Special Inspections • Materials Testing • Environmental Consulting ASTM D4318 - Liquid Limit, Plastic Limit and Plasticity Index of Soils Project: Cannon Slope Stability Date Received: 11-Mar-16 Visual Identification Project#: 16BO13-03 Sampled By: Client Silt with Clay Client: Aspect Consulting Date Tested: 14-Mar-16 So-pleColor Source: B-3 S-6 @ 20' Tested By; K Blodgett -Carrillo y Sample#: B16-0246 Liquid Limit Dctcrminalion Ivelgh r or wet Sol o + Pnn: Weight of Dry Soilr+Pon: weght or Pon: weight or Dry soib: woo, t or h1 oisuwr: 94 ;Llairfule: ium br r of Mons! Plastic Limit Determination d l a, u3 kJ 45 x6 'Weight of "Vel Soils +Pnn; wnighI oT Dry Soils+ Pnn: IvcighI of Pan: Wright or Dry Soils: tveight of �inislnm: Plasticity Chart ago-% 7p0 % 60.07i "1J" line C z 1R096 _ CH or OH- a �� ' MHorOH 7AA9L . CL Of L7 Yp,liili - CL-M- L 409t 60% Yo.o% 20JD% 30.0% rw.o% 541;% 90.ox 70.09E 80.0% W.0% 100.0% tlo.a% Llquid llrnit Liquid Lim it @ 25 Blows: N/A Plastic Limit: N/A Plasticity Index, Ip: N/A ACCRE:1T 5 DQ Cq—iphl Spans Engineering & Tah iml Services PS. 1996-98 Afleealu Aroy WIN Io—.1 l anocn and —rndvl-ol A,. — foil, i-el—fi,-0 +x[cn. III rcpxlcsrc li usl J'o—or Mt' Jw f'i JU NW— 0 pwetn[an.[alk/eaemx -- ft— or regarding our reports is rezencd pading --ill. approval Comments: As received moisttae content = 31.4% Slow dilatancv and inability to roll down to 1 /8"- sample is non -plastic Reviewed by: Corporate -- 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980 Regional Offices: Olympia -- 360.534-9777 Bellingham — 360.647.6111 Silverdale — 360.698.6787 Tukwila — 206.241.1974 Visit our website: www.mtc-inc.net APPENDIX C Selected Slope Stability Results pect Material Name Color Unit Weight (15s/ft3) 5trer Fill ❑ 105 Mohi colluvium ❑ 105 Mohi Landslide Deposits 115 Mohi v-Fraser Nonglacial and Glaciolacustrine Deposits ❑ 120 Mohi Pre -Fraser Undifferentiated D 120 Mohi -200 -150 -100 Cannon Slope Stabilization - Model Setup - Existing Conditions Page 1 of 1 ModelSetup_existing.slim 8/26/2016, 8:31:36 AM pect Material N Fill Colluviu Landslide De Pre -Fraser Nonglacial and GIB Pre -Fraser Undiff Support Name Color Type Solider Pile Micro Pile -250 -200 Cannon Slope Stabilization - Model Setup - Proposed Conditions Page 1 of ModelSetup_proposed.slim 8/26/2016, 8:31:36 AM 0 1K5 0 C T 1CONSULTING Safety Factor 0.0 0.3 0.5 0.8 1.0 1.3 — — 1.5 1.8 2.0 2.3 2.5 2.8 3.0 3.3 3.5 3.8 4.0 4.3 4.5 4.8 5.0 5.3 5.5 5.8 6.0+ Analysis Method: Spencer Surface Options: Surface Type: Circular Search Method: Grid Search Radius Increment: 10 Composite Surfaces: Disabled Reverse Curvature: Invalid Surfaces Minimum Elevation: Not Defined Minimum Depth: Not Defined Surfaces with a factor of safety below 1.500 Loading: Residence Foundation Surcharge 400 psf Unit weight Cohesion Material Name Color (lbs/ft3) Strength Type IPsf1 Fill 105 Mohr -Coulomb 0 Colluvium 105 Mohr -Coulomb 25 Landslide Deposits 115 Mohr -Coulomb 0 Pre -Fraser Nonglacial and Glaciolacustrine Deposits 120 Mohr -Coulomb 100 Pre -Fraser Undifferentiated 120 Mohr -Coulomb 100 -150 -100 M odel5etu p_existing.sli m ScE Cannon Slope Stabilization - Existing Conditions - Static W 50 100 150 200 _ 250 300 Page 1 of 1 350 8/26/2016, 8:31:36 AM Aspect �CON�I.�L71NG Safety Factor 0.0 0.3 0.5 0.8 1.0 1.3 1.5 1.8 2.0 2.3 2.5 2.8 3.0 3.3 3.5 3.8 4.0 4.3 4.5 4.8 5.0 5.3 5.5 5.8 6.0+ Analysis Method: Spencer Surface Options Surface Type: Circular Search Method: Grid Search Radius Increment: 10 Composite Surfaces: Disabled Reverse Curvature: Invalid Surfaces Minimum Elevation: Not Defined Minimum Depth: Not Defined Surfaces with a factor of safety below 1.500 Loading Residence Foundation Surcharge 400psf Material Name Color Unit Weight (Ibs/ft3) Strength Type C Fill 105 Mohr -Coulomb Colluvium 105 Mohr -Coulomb Landslide Deposits ❑ 115 Mohr -Coulomb Pre -Fraser Nonglacial and Glaciolacustrine Deposits ❑ 120 Mohr -Coulomb Pre -Fraser Undifferentiated ❑ 120 Mohr -Coulomb -200 ModelSetu p_proposed.slim -100 Scale: , Cannon Slope Stabilization - Proposed Conditions - Static 1.3 1 ' 0 50 100 150 200 250 Page 1 of 1 House Footprints 400. 00 Ibs/ft2 300 350 8/26/2016, 8:31:36 AM N pest Cannon Slope Stabilization - Existing Conditions - Seismic Page 1 of 1 Safety Factor 0.0 0.3 0.5 0.8 - 1.0 1.3 1.5 1.8 2.0 2.3 2.5 2.8 3.0 3.3 3.5 3.8 4.0 4.3 4.5 4.8 5.0 5.3 5.5 5.8 6.0+ Analysis Method Spencer Surface Options: Surface Type: Circular Search Method: Grid Search Radius Increment: 10 Composite Surfaces: Disabled Reverse Curvature: Invalid Surfaces Minimum Elevation: Not Defined Minimum Depth: Not Defined Surfaces with a factor of safety below 1.500 Loading: Residence Foundation Surcharge 400 psf Seismic Load Coefficient (kh) 0.07g Material Name Color tl"it weight (lhs/ff3) Strength Type Cohesion (psf) I Fill 105 Mohr -Coulomb 50 Colluvium 105 Mohr -Coulomb 25 Landslide Deposits 115 Mohr -Coulomb 50 Pre -Fraser Nonglacial and Glaciolacustrine Deposits 120 Mohr -Coulomb 200 Pre -Fraser Undifferentiated EJ 120 Mohr -Coulomb 200 -200 -150 - M odelSetu p_existing.slim Sca -50 0 50 M 100 150 250 300 A 0.07 350 8/26/2016, 8:31:36 AM Aspect ICON 5 U LT IN Safety Factor 0.0 0.3 0.5 0.8 1.0 i 1.3 1.5 1.8 2.0 2.3 2.5 2.8 3.0 3.3 3.5 3.8 4.0 4.3 4.5 4.8 5.0 5.3 5.5 5.8 6.0+ Analysis Method: Spencer Surface Options Surface Type: Circular Search Method: Grid Search Radius Increment: 10 Composite Surfaces: Disabled Reverse Curvature: Invalid Surfaces Minimum Elevation: Not Defined Minimum Depth: Not Defined Surfaces with a factor of safety below 1.500 Loading Residence Foundation Surcharge 400psf Seismic Load Coefficient (kh) 0.07g Cannon Slope Stabilization - Proposed Conditions - Seismic Material Name Color Unit Weight (Ibs/ft3) Strength Type Cohesion (psf) I Phi (deg) Water Surface Fill 105 Mohr -Coulomb 50 26 Water Surface Colluvium ❑ 105 Mohr -Coulomb 25 30 Water Surface Landslide Deposits 115 Mohr -Coulomb 50 32 Water Surface Pre -Fraser Nonglacial and Glaciolacustrine Deposits 120 Mohr -Coulomb 200 35 Water Surface Pre -Fraser Undifferentiated 0 120 Mohr -Coulomb 200 36 Piezometric Line 1 Scale: 1" = 50' -250 -200 -150 -100 ModelSetu p_proposed.slim Soldier Pile Wall Existing House Footprint .00 Ibs/ft2 ILW t 50 100 150 200 250 360 Page 1 of 1 ® 0 0` ��Wj L 8/26/2016, 8:31:36 AM APPENDIX D Structural Calculations 1,___.1.1Is) :1► 11 Project No.: 150376 July 11, 2016 To: City of Federal Way cc: Marty and Katherine Cannon From: Aspect Consulting Re: Cantilevered Soldier Pile Wall Structural Calculations We analyzed cantilevered retaining wall options with exposed wall face heights between 4 feet and 12 feet. The wall heights were determined to protect the upper slope steep slope at 29437 1 Oth Ave SW, Federal Way, Washington from shallow failures. The wall heights were designed to optimize the exposed wall face height while maintaining a cost effective solution to stabilize the slope. We determined that an 8-foot wall was feasible with HP 12 x 53 piles. We made several assumptions in our calculations for fluid equivalent lateral earth pressures and shoring calculations: ■ Triangular apparent envelope ■ At active pressures ■ For the seismic case, horizontal acceleration coefficient = 0.07g ■ Log Spiral Analysis ■ 1.5x safety factor for passive pressures ■ Passive arching width of 2.513 Static Case: bep h[IIi ----------------- 5 10 15 20 25 Force 6qu�Lbiiwn 0 1 ksf 30 <ShoringSuite> CIVILIECHSORWARE USA www.civillech.com Licensed to 4324324234 3424343 Date: 7/8/2016 File: UNTITLED Wall Height=8.0 Pile Diameter-2.0 Pile Spacing=8.0 Wall Type: 2. Soldier Pile, Drilled PILE LENGTH: Min. Embedment=18.61 Min. Pile Length=26.81 MOMENT IN PILE: Max. Moment=92.82 per Pile Spacing=8.0 at Depth=16.75 PILE SELECTION: Request Min. Section Modulus = 46.9 in3/pile=768.16 cm3/pile, Fy= 36 ksi = 248 MPa, Fb/Fy=0.66 -> Piles meet Min. Section Requirements: Top Deflection is shown in (in) W8X58 (1.18) HP10X57 (0.92) W10X45 (1.09) HP12X53 (0.69) W12X40 (0.88) HP13X60 (0.54) HP14X73 (0.37) W14X34 (0.79) W16X31 (0.72) HP16XB8 (0.24) W16X89 (0.21) HP16X101 (0.21) W16X100 (0.18) HP16X121 (0.17) DRIVING PRESSURES (ACTIVE, WATER, & SURCHARGE): 21 P1 22 P2 Slope 0 0 5 0.190 0.038 5 .19 55 1.790 0.032 PASSIVE PRESSURES: Pressures below will be divided by a Factor of Safety =1.5 Zi P1 22 P2 Slope 10 .28 55 6.580 0.1400 ACTIVE SPACING: No. Z depth Spacing 1 0.00 8.00 2 8.00 2.00 PASSIVE SPACING: No. Z depth Spacing 1 8.00 5.00 UNITS: Width, Spacing, Diameter, Length, and Depth - ft;Force -kip; Moment -kip-ft Friction, Bearing, and Pressure - kst Pres. Slope - kip/ft3; Deflection - in Seismic Case: a----------- ----- 5 ------------------------------------- 10 v 15 20 25 m Force F�wium 30 0 1 ksf <ShoringSuite> CIVILTECHSOFTWARE USA www.civiltach.com Licensed to 4324324234 3424343 Date:7/8/2016 File: UNTITLED Wall Height=8.0 Pile Diameter-2.0 Pile Spacing=8.0 Wall Type: 2. Soldier Pile, Drilled PILE LENGTH: Min. Embedment=20.04 Min. Pile Length=28.04 MOMENT IN PILE: Max. Moment=113.93 per Pile Spacing=8.0 at Depth=17.31 PILE SELECTION: Request Min. Section Modulus = 57.5 in3/pile=942.91 cm3/pile, Fy= 36 ksi = 248 MPa, Fb/Fy=0.66 -> Piles meet Min. Section Requirements: Top Deflection is shown in (in) W8X67 (1.30) HP10X57 (1.20) W10X54 (1.16) HP12X53 (0.90) W12X45 (1.01) HP13XB0 (0.70) HP14X73 (0.48) W14X43 (0.82) W16X40 (0.68) HP16X88 (0.32) W16X89 (0.27) HP16X101 (0.27) W16X100 (0.24) HP16X121 (0.22) DRIVING PRESSURES (ACTIVE, WATER, & SURCHARGE): Z1 P1 Z2 P2 Slope 0 0 5 0.190 0.038 5 .19 55 1.790 0.032 Earthquake 0 .024 11 0.024 0 PASSIVE PRESSURES: Pressures below will be divided by a Factor of Safety =1.5 Z1 P1 Z2 P2 Slope 10 .28 55 6.580 0.1400 ACTIVE SPACING: No. _ Z depth Spacing 1 0.00 8.00 2 8.00 2.00 PASSIVE SPACING: No. _ Zdepth_ Spacing 1 8.00 5.00 UNITS: Width,Spacing, Diameter, Length,andDepth -ft; Force - kip; Moment -kip-ft Friction,Bearing,and Pressure - ksf; Pres. Slope - kip/ft3; Deflection - in r ,,,Aspect C��n�a�, - Project: Su Project No: ESO 3-76 Date: -:1d16 By: _ 7aF CONSULTING Subject: i,-, f eo 0-4... r.:.', Page: 1 of � AC4N\P- +V S (-r to v- O - 61 65s - 0 = ZS' u d_ 36 C! to Spe_o = 3 ff �arr�ri�+c c�r�t�s�ro►� ��'r'b 6of�o�, F(bv,IVAvFA-c-1,z-6a Ke-=o.Z7- PaSSIVc- Prr-ssoreS : ]Fcb-,, Kr = I_IG- Iq-op ' APPENDIX E Project Plans APPENDIX F Ecology Well Log 0 CL �l s r C 0 C 0 E L 0 C dJ s L 0 C �.r ❑ s r.+ C t� L L M O Z fn 0 0 .a _0 0 ci W 0 J..1 C CW G L CL 0 fit s H Z 13 Please print,, sign an eturnto the Department of Ecology y �" - 7S -- / 7 Curl•eut W ater Well Report AN 25 2007 r WF04696 (page l of2) Original —Ecology, Pt rap}'—ast�ur, ind copy — driller Notice of Intent No. [CBLOGsI' t ;'' Uu +i . _rJ+rUllique Ecology Well ID Tog No. APN017 Coush•uction/Decommission iiliELl I,ti?iL�tNii' �t;•'t{ ✓❑Construction Water Right Permit No. ❑ Decommission OAIGINALINS'TALL.4-TIONNotice Property 0umerNanle Lakehaven Utility District gfJwentM1jnbe7' Well Street Address 3] 531 1st Avenge South PROPOSED USE: ❑ Domestic ❑ Industrial 8 Mmticipal CiY Federal Way C"oun VLlg ❑❑ Ir DeWater rigation ,m Test Well Oder y tY TITE OF IVORK: Owner's rnuuber of well (if more than one) 4 33 m Nets- tvell ❑ Reconditioned :Verhod : ❑ Dug ❑ Bored ❑ Driven ❑ Deepened ❑ Cable m Rotary ❑ letted DIMENSIONS: Dtanteter of well 8 inches, drilled 1093 ft. Depth of completed well 985 ft. Casing m Wcldw 8 Divn from +1 ft. to 833 ft. Installed: e Liner installed F. Di am. from 853 ft, to 910 R Threaded 8 Diam. from 465 ft. to 990 n. Perforalious; []Yes tw Type of perforator used SIZE of perfs um by _ In and no. of per fr,Rum _ A. to _A. Screens: m 1'es ❑ No ❑ K-Pac Locauou \�.lnnfaClnl'ef SNaol[ Alloy Type 304SS Sianda rsre Wrao Model No SCR Dranr 8 Stot size .0-M ham $� fl to 853 0 Dram 8 Slot size-.0_a0 _frnug1�8.to.ft. Gtarel/Filter parked: ❑ Yes O No ❑ Size of gravel/sand \laterials placed from ft. to A. Surface Seal:: m Yes ❑No To what depth? 272 ft. Aaterial used is seal_ rrttortite mour Did any snrala contain unusable water° .❑ Yes - . ,ONo Type of n•ater? ' ' Depth of strzta %lethod of seahne strata olr PC\1P: il-[anufacturer'sNiirie' Type w H.P: WATER LEVELS: an surface elevation above mean sea level ft. Static level 299 87 ft. below top of well Date 12/13/06 Artesiaupressure Ibs.persquareineh Date Artesian water is controlled bs• 117ELL TESTS: Drawdown is amount water level is lowered below static level Was a pump test made? m Yes ❑ No If yes, by wham? BoartLngyear Yield: 240.7 gal.;ruin. with 67 ft. drawdown after 0.083 his. Yield.240.7 gal:ntiuwilb97.7 _ft.(tmwdoasnafter 24.0 M. Yield: gal.!mut. with ft. dratvdoem after hrs. Rc: oven• darn !rime taken as _ero when pump turned o ff7 (u•orer leval measured front sr -all rr, top ra trter• reveU Time Water Level Tune Water Level Time Water Level 1 min 339 02 20 in 334.30 6lir 317.60 2 min 34303 l lu 328.53 24 hr 311.70 1 Orlin 337 55 ' rtr 321.70 4 day 308.1 Date oftest 10!11i06 Bailer test gabirim. with ft- tbawdown after firs. .Atnest _ gal irnhr with stem set at R. for his. .Artesian tloav — `rkp.rri. Date Teniperamueofsvateu Was a chemical analysis made'? ❑Yes ❑No Location NE1/4-1/4 SE 1,4 Sec 7 Tayn 21 R4 E W mcle lV0.Tt 0°e LatlLong (s, I. r Lat Deg _ Lat Mill/Sec still REQUIRED ) Long Deg Long Min/Sec Tax Parcel No, 0721049014 CONSTRUCTION OR DECOMARSSION PROCEDURE Farmation: Describe by color, character, size of material and structure, and the kind and nature of the material in each stratum penetrated, with at least one entry for each change of infornatau iadicale all water eucowrtercd. USE ADVITIDNAL, SHEETS IF NEC'ESSAP.1'- MATERIAL I FROM I TO Brown silty, grax-els & cobbles 0 129 Brown silty sand w/ small gravels 129 141 Dirty brown sand & sutall gravel (water bearing) 141 146 Clean coarse sand & gravel w/ water 146 156 Sand and gravel w/ cobble seams (water bcttrin 156 188 Sand and Pravel (water bearing) 188 1 225 Sand and lnr a gravel (water bearing) 225 235 Siuid and small gravel (water -bearing) 235 245 Sand and Wge,gravel (wafer bearing) 243 Z'52 Sandy grev silt avb• and seami' "- 252 263 Grey silt - tight, hard. dry • 263' 272 Clayey silt: tight; grey hard, sticky 272 288 Grey silt bound gravels and cobbles 288 302 Dirty gravel and cobbles . -- 302 314 Scold, gravel and cobbles - cleaner 314 325 Sand• gravel and cobbles 325 332 Large cobbles, juavel, very hard, dirtier 332 349 Gravel, sand and cobble, some binder, very hard 349 352 Gravel, sand and cobbles - bard 352 356 Course gravel attd sands with cobbles - hard 356 411 Med. sand w/ sutall gravels w/ scattered cobbles 411 418 Fine to nteditun sand with small gravels 418 428 Sand attd gravel ntix 428 433 Fine / coarse sand and gravel w•/ some cobbles 433 450 Grey sands and gravels (water bearing) 450 461 Sand and gravels w/ some cobbles (water bearing) 461 477 Fine I medium sand w/ a trace of vets 477 501 Fine silt. medium sand, trace of srav-els 501 515 I CONTINUED ON PAGE 2 1 1 1 E start Date 05/04/06 Completed Date 12!13/06 I WELL C'bNSTRis•C'TIUN-CERTIFICATION:. I constructed an(Vor accept responsibility for construction of this well, and its compliance with -all �4'ashinatou.avelLconshitctirnt standards. Materials used and the information repotted above nrctrue to lily best kuowledge•an(1 belief. _ Driller.Enghteer!Trantee -Name (Print) ; uss Otto Drilling Company Bout Lan 'ear / Geo- ech Driller.-Eugi eer%Tramee Signature 7�r�. _ Address 19700 SW Teton Ave Driller or irainee License No. 2660 City, State, Zip Tualarin- OR 97062 IIf TRIINEE, Contractor's Drlllel's Licensed\o. Registration No BOARTIG055PZ —Date 1-19-06 Driart's Signature Ecology is an Equal Opportunity Employer. ECY 050-1 20 (Rev 2103) Please prinjt sign' arid`. eefurn=ta'the Department of Ecology Water Well Report jm� 25 2007Curreut n N,otice of Intent No. WE046976 (page 2 of ) r „ Origlual —Ecology. Vic —a 2°dj tg ;tltiller, „( Li,JL?rL C C 0 L 0 G Y 1`' :i l �`i l.i. IPrlt' I 'Ni nique Ecology Well ID Tag No. APNo17 �-OI1St1'llC ilOII/DeCO111rri15S1011 0✓ Construction Water Right Peltliit No. Decommission ORIGIM4LLVST.4LLATI01VNofice property Owner Name LakehavilUtility District q%Iutexl NfnNhet' 31531 1st Avenue South Well Street Address _ _ PROPOSED USE: Domestic ❑ industrial L3 Municipal ❑DeWnler Irrigation In Test Well Other TYPE Or WORK Owner's number of well (if more than one) # 33 0 New well ❑ Reconditioned 3ferhod : ❑ Dug ❑ Bored ❑ Driven ❑ Deepened ❑C;kble m Rotary• ❑ Jetted DFUENSiONS: Diameter ofwell inches, drilled ft Depth of completed well ft. Casing ❑Welded Dharn from ft to ft. Installed: Linei uistalled Dime- from ft to fl. e Threaded Diann. from ft- to ft. Perforadous: []Yes No Type of perforatoi used SIZE of perfs in. by _ w and no of perfs_from _ ft. to fl. Screens: ❑1'e5 []No ❑K-Pac Location Manufacturers Name Type Model No. Dian. —Slot size from fl to ft Diam. Slot size from ft. to ft. Ct avel/riller packed: ❑ 1'es ❑ No ❑ Size of gravel/saad Matenals place(I from ft. to ft Surface .Seal:: ❑ Yes ❑ No To what depth? ft. 'statenal used in seal Did any strata conram unusable water? ❑ Yes ❑ No Type of water' Depth of strata Method of sealuig strata off PUMP: Manuf.10LI r s Nanhe Type: H.P. WATER LEVELS: Land -surface elevation above mean sea level ft. Static level ft below top ofwell Date Adesiarm pressure Ibs per squareinch Date Artesian wafer is coulrolled by (cap. valve, etc) WELL TESTS: Diawdown is amount water level is lowered below static level Was a pump test made° ❑ Yes [3 No If yes, by whom? Yield gal.amin will] ft drawdown after lus. Yield gal.!nun wilh ft drawdonro after lin. Yield. galarn. with ft. dnwdown after his Re: oven• darn +mxe taken its -ero when punip nnnod q0) (carer An -al rnaasured from wall top to ira;er (ever/ , Time Water Level Time Water Level Time water Level Date of rest Bailerleit cal./nun with ft dran•downafter firs. Airtest__ gal nt6h with stein set at ft. for hrs. Atlesnu flocs € p tin Date Tenyherature of water was a chenucal analysis made? ❑ Yes ❑ No City Federal Way County King Location 11E114-1r4 SE 1/4 Sec 7 Twil21 R`� EVMor '7 cvcir yl'tkTf one Lat/Long (s, t, 1 Lat Deg Lat Milr/Sec still REQUIRED ) Long Deg Long Min/Sec Tax Parcel No. 0721049D14 CONSTRUCTION OR DECOMMISSION PROCEDURE Formation Describe by color, character, size of matertat and structure, and the kind and nature of the material in each stratum penetrated, with ai least one entry for each change of information indicate allwater encountered. 'SE ADDITIO:G+,L SHEETS IF VECESSARY. MATERIAL FROM TO Dark gray sand 515 535 Gray sandy silt with some small gravel 535 570 Sandy silt - gray 570 575 Small gravels and coarse sand 575 610 Gravel - small to medium 610 655 Silly gravel - small to medium 655 679 Clayey silt w/ some small gravels 679 760 Gray silt and gravels 760 775 Gray clayey silt with traces of gravel 775 800 Grav clavev silt 800 940 Gray sandy silt w/ sane Kavels 940 955 Gray silt (soft) with some sand 1955 975 Clayey silt (gray / blue) with some sand 1 975 1 1093 SEE ATTACHED AS -BUILT DIAGRAM FOR CONSTRUCTION DETAILS 12" Casting 272.5 to 515 feet 8 inch casing cut and overshot at 290 feet. I Dual Slnale Traps n 685 mid 775 feet l . —_ I 1 Backrill Cement 985-997 Sand 997-1000 Gravel 1000-1093 Start Date 05iO4/06 Completed Date 12113M6 IVELL C_'ONSTRUC'TION CERTIFICATION: I constructed and/or accept responsibility for construction of this Nvell, and its compliance with all FVashington vvell construction standards. 'I'vlatelials used and the information reported above nre hue to nay best know -ledge and belief. Di illeriDwineer:Tramee Name (Friut tss 011 Drilling Company Boart Loxigyeat / o- Driller. Lngincer•Trainee Signamure _ Address 19700 SW Telpn Ave11 - Duller or trainee License No 3660 City, State, Zip Tualatin. OR 97062 if TlZ INEE, Contractor's D ri l l n'i Licensed yo. Registration No )30ARTli=FZ Date 01-19-07 Di taei's Signntnm a Ecology is an Equal Opportunity Employer. ECY 050-1-20 (Rev 2103) Lakehaven Well 33 Notice of Intent: WE04696 Tag Number: APN017 Oft 100 ft Bentonite Grout 0 to 272 ft 200 tt Cement 272 to 282 ft 20-40 Sand 282 to 286 ft 300 ft— Gravel 286 to 290 ft 400 ft Cement 413.8 to 496.5 ft 500 ft Gravel 496.5 to 541.5� 600 ft Gravel 635 to 685 ft 700 ft 800 ft 900 tl 1000 it-- 20-40 sand 997 to 1000 ft 1100 Boring Diameter: - 16" from 0 to 48 feet - 12" from 48 to 1093 feet. 12" Casing: 272.5 to 515 feet. 8" Casing: - +1 to 833 feet w/ cut and overshot @ 290' - 853 to 910 feet - 965 to 990 feet (tail pipe) 8" Screen: - 833-853 feet - 910-965 feet Shale Traps: - 685 feet - 775 feet �5.5 to 496.5 ft Shale Traps 685 feet Shale Traps 775 feet 985 to 997 ft Gravel 1000 to 1093 feet ***Width not to scale.*** **Length Approximate Scale** 4j L O a . a� d t H S Inch cut and overshot nia yarn Lakehaven Well 33 Notice of Intent: WE04696 Tag Number: APNO17 RECEIVED) �r Mike Maisen JUL 112016 r` CITY OF FEDERAL VV From: CDS Kaehler, Gretchen (DAHP) <Gretchen.Kaehler@DAHP.wa.gov> Sent: Tuesday, July 05, 201612:15 PM To: Mike Maisen Z Subject: RE: Cultural Evaluation Waiver for Slope Project at 29437 loth Ave SW Federal Way. Attachments: City of Federal Way Inadvertent Discovery Plan.pdf Z Hi Mike, Gx I don't have any specific concerns regarding this project. I would recommend and Inadvertent Discovery Plan and have attached one for your use. Please feel free to contact me if you have any questions. Best, Gretchen From: Mike Maisen[mailto:mmaisen@aspectconsulting.com] Sent: Thursday, June 30, 2016 2:12 PM To: Kaehler, Gretchen (DAHP) Subject: Cultural Evaluation Waiver for Slope Project at 29437 10th Ave SW Federal Way? Hi Gretchen, Thank you for talking over my question today on the phone about the 29437 10th Ave SW in Federal Way Federal Way slope project and if a waiver of the cultural evaluation is appropriate for this site. As you requested, below is a brief project summary along with a site map and conceptual site plan for our proposed shoring wall. Please review and let me know if this site does qualify for a waiver. Project Summary The Cannon residence is located at 29437 10th Ave SW in Federal Way, WA and lies near to the top of a steep coastal bluff. Within the last decade, several shallow landslides have occurred near the residence on the upper slope. To mitigate shallow landslide hazards, we are stabilizing the upper portion of the steep slope to protect the residence from future shallow landslides. We are stabilizing it with a soldier pile wall, designed as a cantilevered (meaning no tieback anchors are required) soldier pile wall with 40-foot piles spanned by timber lagging. The total excavation required for this project is relatively minor (less than 300 cubic yards). All excavation and fill activities will take place near the top of the steep slope (within the upper —10 feet); minor temporary construction -equipment disturbance to the lawn will be the only impact to the upland portion of the site. The project is located approximately 200 feet upslope from the Puget Sound shoreline and will not cause any impact to the shoreline, shoreline vicinity, or remainder of the steep slope. Thank you, Mike Mike Maisen I Sr. Technical Editor I Direct: 206.838.58391 Cell: 206.696.4931 Aspect Consulting LLC 1 401 Second Avenue S, Suite 201, Seattle 98104 1 www.aVectcon5vl_tin_.c rn This email is intended solely for the addressee(s) and may contain confidential or legally privileged information. If you are not the intended recipient, please immediately alert the sender by reply email and delete this message and any attachments without storing, copying, distributing, or using the contents. PERMIT #: 16-1 03326-00-S F ADDRESS: 29437 1 Oth Ave SW °ROJECT: Soldier Pile Wall CANNON SLOPE STABILIZATION DATE: 7/ 12/ 16 Inadvertent Archaeological and Historic Resources Discovery Plan King County In the event that any ground -disturbing activities or other project activities related to this development or in any future development uncover protected cultural material (e.g., bones, shell, antler, horn or stone tools), the following actions will be taken: 1. When an unanticipated discovery of protected cultural material (see definitions below) occurs, the property owner or contractor will completely secure the location and contact: a. The property owner and/or project manager; b. A professional archaeologist; c. The Department of Archaeology and Historic Preservation (DAHP) (Gretchen Kaehler, Assistant State Archeologist, Local Governments, 360-586-3088); d. The Tulalip Tribe (Richard Young, 360-716-2652); e. The Snoqualmie Tribe (Steven Mullen -Moses, 425-888-6551); Dennis Lewarch, THPO, Suquamish Tribe (360-394-8529 f. Laura Murphy, Muckleshoot Tribe (253-876-3272) g. The Duwamish Tribe (Cecile Hansen, Chair 206-431-1582). 2. If the discovery is human remains, the property owner or contractor will stop work in and adjacent to the discovery, completely secure the work area by moving the land -altering equipment to a reasonable distance, and will immediately contact: a. The property owner; b. The City of Federal Way Police Department (253-835-6700) and; c. The King County Medical Examiner, Richard Harruff (206-731-3232) to determine if the remains are forensic in nature; d. If the remains are not forensic in nature the Department of Archaeology and Historic Preservation (DAHP) Guy Tasa 360-586-3534); will take the lead on determining the appropriate method of treatment for the remains and will consult with the affected tribes; e. A professional archaeologist; and 3. Cultural material that may be protected by law could include but is not limited to: a. Buried layers of black soil with layers of shell, charcoal, and fish and mammal bones (Figure 1). b. Non -natural sediment or stone deposits that may be related to activity areas of people; c. Stone, bone, shell, horn, or antler tools that may include projectile points (arrowheads), scrapers, cutting tools, wood working wedges or axes, and grinding stones (Figures 2 and 3); d. Stone tools or stone flakes (Figures 2 and 3); e. Buried cobbles that may indicate a hearth feature (Figure 4); f. Old ceramic pieces, metal pieces, tools and bottles (Figures 5 and 6); and g. Perennially damp areas may have preservation conditions that allow for remnants of wood and other plant fibers; in these locations there may be remains including: • Fragments of basketry, weaving, wood tools, or carved pieces; and • Human remains. 4. COMPLIANCE WITH ALL APPLICABLE LAWS PERTAINING TO ARCHAEOLOGICAL RESOURCES (RCW 27.53, 27.44 and WAC 25-48) AND WITH HUMAN REMAINS (RCW 68.50) IS REQUIRED. FAILURE TO COMPLY WITH THESE i REQUIREMENTS COULD RESULT IN A MISDEMEANOR AND POSSIBLE CIVIL PENALTIES AND/OR CONSTITUTE A CLASS C FELONY. 7 �11 Figure 1:Shell midden 2 2 Figure 2: Example of stone tools Figure 3: Example of stone flake and tools. 4 �`. mow. -+ • � v VC.,:. . ��. :� ,,fir•- � .. _. - _ ,�,_ k� _� -ter �� •• _ ; Figure 5: Example of historic artifacts from debris scatter. Figure 6: Example of bottle from historic debris dump. 5 6