17-105489-Pavement Analysis Report-11-12-2021-V2Earth Science + Technology
Pavement Analysis Report
Weyerhaeuser Way South
320th Street to 336th Street
Woodbridge Business Park
Federal Way, Washington
for
Federal Way Campus, LLC
August 16, 2021
Pavement Analysis Report
Weyerhaeuser Way South
320th Street to 336th Street
Woodbridge Business Park
Federal Way, Washington
for
Federal Way Campus, LLC
August 16, 2021
1101 South Fawcett Avenue, Suite 200
Tacoma, Washington 98402
253.383.4940
Pavement Analysis Report
Weyerhaeuser Way South
320th Street to 336th Street
Woodbridge Business Park
Federal Way, Washington
File No. 22247-004-02
August 16, 2021
Prepared for:
Federal Way Campus, LLC
11100 Santa Monica Blvd., Suite 850
Los Angeles, California 90025
Attention: Dana Ostenson
Prepared by:
GeoEngineers, Inc.
1101 South Fawcett Avenue, Suite 200
Tacoma, Washington 98402
253.383.4940
Lyle J. Stone, PE
Associate Geotechnical Engineer
LJS:tt
Disclaimer: Any electronic form, facsimile or hard copy of the original document (email, text, table, and/or figure), if provided, and any attachments are only a copy
of the original document. The original document is stored by GeoEngineers, Inc. and will serve as the official document of record.
8/16/2021
August 16, 2021| Page i
File No. 22247-004-02
Table of Contents
1.0 INTRODUCTION AND PROJECT UNDERSTANDING ........................................................................................ 1
2.0 SCOPE OF SERVICES ...................................................................................................................................... 1
3.0 SITE CONDITIONS ............................................................................................................................................ 1
3.1. Geology Review ........................................................................................................................................... 1
3.2. Surface Conditions...................................................................................................................................... 2
3.3. Existing Pavement Conditions .................................................................................................................... 2
3.3.1. Design Segments ........................................................................................................................ 2
3.3.2. Existing Pavement Sections ....................................................................................................... 2
3.3.3. Falling Weight Deflectometer Testing ........................................................................................ 2
3.3.4. Visual Condition Survey .............................................................................................................. 3
4.0 PAVEMENT ANALYSIS AND DESIGN .............................................................................................................. 3
4.1. Anticipated Vehicle Loading ....................................................................................................................... 3
4.2. Pavement Analysis and Design Parameters ............................................................................................. 4
4.2.1. Pavement Design Criteria ........................................................................................................... 4
4.2.2. Subgrade and Material Strength Coefficients ........................................................................... 5
5.0 PAVEMENT SECTION RECOMMENDATIONS ................................................................................................. 5
5.1. Design Approach ......................................................................................................................................... 5
5.2. Pavement Overlay Considerations and Recommendations ..................................................................... 5
5.3. Recommended Pavement Sections........................................................................................................... 6
5.3.1. Segment 1 –South 336th Street Roundabout to Midpoint of the Woodbridge Business
Park Development ...................................................................................................................... 6
5.3.2. Segment 2 –Midpoint of the Woodbridge Business Park Development to South 323rd
Street ........................................................................................................................................... 6
5.3.3. Segment 3 – South 323rd Street to South 320th Street ........................................................... 6
5.4. Construction Recommendations ............................................................................................................... 7
6.0 LIMITATIONS ................................................................................................................................................... 7
LIST OF FIGURES
Figure 1. Vicinity Map
Figure 2. Site Plan
APPENDICES
Appendix A. FWD Results and Data
Appendix B. Report Limitations and Guidelines for Use
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File No. 22247-004-02
1.0 INTRODUCTION AND PROJECT UNDERSTANDING
This geotechnical engineering report presents a summary of our services for the Weyerhaeuser Way
Improvements project in support of the Woodbridge Business Park Property in Federal Way, Washington.
The project will ultimately include roadway improvements on two segments of Weyerhaeuser Way. The
southern section will be from the eastbound State Route (SR) 18 on and off ramps to the roundabout that
connects to 33rd Place South. Analysis of the southern section was provided in our report Geotechnical
Engineering Services Report-Revised, Weyerhaeuser Way South, 320th Street to SR 18, Weyerhaeuser
Campus Property, dated January 30, 2020. The northern section of the project will be from South
336th Street to South 320th Street. This report addresses the proposed improvements to the northern
section. A Vicinity Map of the approximate project boundaries is provided as Figure 1. A Site Plan is provided
as Figure 2.
We understand that the City of Federal Way (City) has required that: “The applicant must perform pavement
evaluation demonstrating that the standard pavement section for a Type “K” street is adequate to handle
the expected traffic load generating by the proposal.” The City previously provided guidance for the southern
section stating the design criteria should be in accordance with American Association of State Highway and
Transportation Officials (AASHTO) Guide for Design of Pavement Structures (1993) with additional guidance
from Washington State Department of Transportation (WSDOT) Pavement Policy September 2018 for local
data, as applicable.
Based on information provided by ESM and TENW, the proposed traffic with the expected truck load will be
based on the existing daily traffic volume with an additional 256 truck and trailers per day traveling north
of the Woodbridge Business Park (128 northbound and 128 southbound) and an additional 298 truck and
trailers per day traveling south of the Woodbridge Business Park (149 northbound and 149 southbound).
2.0 SCOPE OF SERVICES
Our services for this project have been performed in accordance with our proposal dated April 30, 2021
and signed August 9, 2021. These services included performing a visual pavement condition survey,
reviewing existing subsurface information collected in 2017 and providing recommendations for pavement
improvements or overlays as appropriate.
3.0 SITE CONDITIONS
3.1. Geology Review
We reviewed the Geologic Map of the Poverty Bay 7.5-Minute Quadrangle, King and Pierce Counties,
Washington (Booth, D. B., Waldron, H. H., and Troost, K. G.: U.S. Geological Survey SIM-2854, scale
1:24,000).
The mapped geologic unit across the entire project area is Vashon till (Qvt). Vashon till deposits are
considered glacially consolidated soils as they were deposited below glacial ice. Glacially consolidated soils
are typically dense to very dense due to being compressed (consolidated) by the weight of the overlaying
glaciers. Glacial till typically consists of a homogenous mixture of silt, sand, gravel, cobbles, and boulders.
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File No. 22247-004-02
3.2. Surface Conditions
Weyerhaeuser Way South is in southeastern Federal Way, Washington. The project area is between the
roundabout at South 336th Street at the south extent and the intersection of South 320th Street at the north
extent. South 323rd Street connects to the west about 1,100 feet south of 320th Street. The roadway
between South 336th and South 323rd is two traveled lanes, one in each direction, with a paved shoulder,
and no curbs or sidewalks. This portion of the site is generally wooded with occasional driveways.
The roadway between South 323rd and South 320th includes two traveled lanes with a center turn lane,
bike lanes, planter strips, and sidewalks. The west side of the street is developed with commercial buildings.
The east side has one commercial development at the intersection with South 320th Street.
3.3. Existing Pavement Conditions
3.3.1. Design Segments
The project area has been divided into three design segments based on existing pavement conditions,
measured subgrade resilience, and design loading. These segments, from south to north, are:
■ Segment 1 – Extending from north of the roundabout at South 336th Street to roughly the midpoint of
the Woodbridge Business Park Development. Indicated from Station 50+00 to 64+00.
■ Segment 2 – Extending from roughly the midpoint of the Woodbridge Business Park Development to
South 323rd Street. Indicated from Station 54+00 to 87+00.
■ Segment 3 – Extending from South 323rd Street to South 320th Street. Indicated from Station 87+00
to 98+00.
Note that the referenced stationing indicated on Figure 2 was developed for the pavement study and is not
related to any other stationing developed for geometric roadway design.
3.3.2. Existing Pavement Sections
We reviewed project plans for roadway improvements in the area. Based on plans for the South 336th Street
and Weyerhaeuser Way Roundabout, dated January 30, 2004, new pavement sections consist of 8 inches
asphalt concrete (AC) over 6 inches crushed surfacing top course (CSTC). Based on plans for East Campus
Corporate Park Off Site Road Improvements Weyerhaeuser Way South and South 320th Street dated
February 17, 1999, Weyerhaeuser Way consists of a combined overlay with new pavement in widened
areas. The center of the road consisted of a 2.5-inch overlay of the existing asphalt pavement. This overlay
extends over the center turn lane and about half of each travel lane. The widened areas consist of 6 inches
of AC over 2 inches of CSTC.
We did not core the pavement. These thicknesses have not been independently confirmed. We also do not
have information regarding existing pavement thicknesses for the segments between the South 336th
roundabout and South 323rd Street.
3.3.3. Falling Weight Deflectometer Testing
Deflection testing by means of Falling Weight Deflectometer (FWD) was completed by Pavement Services
Inc. (PSI) on June 7, 2017. Tests were performed in the north and southbound directions at approximate
200-foot intervals. Test results were normalized to a 9,000-pound load. A summary of the back-calculated
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File No. 22247-004-02
subgrade modulus and pavement structural numbers for each direction are summarized in Table 1, below.
FWD test data and back-calculations are included in Appendix A of this report.
TABLE 1. FWD RESULTS SUMMARY
Segment and Travel Direction Average (Mean) Subgrade
Modulus (Mr) (psi)
Minimum Subgrade
Modulus (Mr) (psi)
1st Quartile Subgrade
Modulus (Mr) (psi)
Segment 1 Northbound 9,912 8,031 9,003
Segment 1 Southbound 10,076 6,546 9,427
Segment 2 Northbound 13,593 10,142 11,906
Segment 2 Southbound 14,321 8,877 13,450
Segment 3 Northbound 10,027 6,808 9,524
Segment 3 Southbound 11,666 8,967 11,459
3.3.4. Visual Condition Survey
We completed a visual condition survey of the existing pavement on July 6, 2017. We generally followed
the techniques described in the AASHTO/Federal Highway Administration (FHWA) Pavement Moisture
Accelerated Distress Identification System. On August 10, 2021, we completed a similar visual condition
survey to identify any significant changes from our 2017 evaluation.
Segments 1 and 2 (combined area from South 336th roundabout to South 323rd Street) did not appear to
have appreciable or significant pavement degradation between 2017 and 2021. Although the pavement
evaluation was not quantitative (i.e., no crack counts with detailed length measurements), the location,
type, and severity of the pavement distress noted was consistent between the 2017 and 2021 surveys.
The exception is a few locations just north of the South 336th Street roundabout were some minor potholes
observed in 2017 had been patched and repaired.
Pavement distress in these segments consisted of minor linear cracking with to moderate linear cracking
in isolated areas.
Segment 3 (area from South 323rd Street to South 320th Street) did appear to have more degradation since
our 2017 survey. In 2017, we noted minor to moderate transverse and lateral cracking. In 2021, we
observed more moderate transverse and lateral cracking that in many locations was transforming into
minor block cracking. Additionally, we noted isolated areas (less than 4 feet in length) of minor to moderate
fatigue cracking with some minor pothole development.
The observed pavement damage was predominantly in the travel lanes. We did not note rutting or extensive
fatigue cracking that would be a sign of extensive subgrade degradation.
4.0 PAVEMENT ANALYSIS AND DESIGN
4.1. Anticipated Vehicle Loading
Traffic volumes were provided by TENW. Existing traffic conditions were based on a field traffic count
performed in June 2017. TENW also provided estimated growth rates and the estimated increase in truck
traffic as a result of the proposed development. These estimates include the predicted effects of the
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File No. 22247-004-02
proposed developments. TENW predicts an additional 298 truck trips per day traveling to or from South
336th Street (149 in each direction). These truck trips were applied to design Segment 1. TENW predicts
that the development will result in an additional 256 truck trips per day traveling to or from South
320th Street (128 in each direction). These truck trips were applied to design Segments 2 and 3.
The AASHTO design methodology quantifies traffic loading in terms of 18-Kip equivalent single-axle loads
(ESALs). In order to evaluate the pavement and provide a design we converted the traffic estimates to
ESALs. We assumed that every automobile (bicycles, cars, and light trucks) applies an average of
0.0013 ESALs. We assumed that the trucks would be carrying standard shipping containers or similarly
weighted trailers. We used a typical truck weight and a standard distribution of shipping container weights
(developed by Port of Long Beach) to calculate an average loading per truck. Based on this method, we
estimate that every truck applies an average of 1.2 ESALs.
The estimated ESALs over the entire design life were determined by calculating the current daily ESAL value,
based on the existing traffic counts, and extending the daily value over a 20-year design life with the
corresponding growth rates and increase in truck traffic. Because the proposed development will cause
additional traffic on top of the additional truck traffic, a higher growth than typical rate was used to
determine the ESALs. We used a growth rate of 4 percent in our calculations.
The variables provided to us by TENW and the resulting ESAL calculations for a 20-year design period are
summarized in Table 2 below.
TABLE 2. DESIGN ESAL SUMMARY
Design Segment and Traffic Count
Location
Average Daily Small
Vehicle Traffic
(One Way)
Average Daily Truck
Traffic
(One Way)
Total EASLs
(20 years)
Traffic Count North of S 336th (NB) 3,199 40 --
Traffic Count North of S 336th (SB) 2,930 40 --
Segment 1 Design Values 3,200 189 3,690,000
Traffic Count South of S 323rd (NB) 2,968 19 --
Traffic Count South of S 323rd (SB) 3,007 67 --
Segment 2 Design Values 3,010 195 3,810,000
Traffic Count North of S 336th (NB) 2895 50 --
Traffic Count North of S 336th (SB) 2776 19 --
Segment 3 Design Values 2,900 178 3,480,000
4.2. Pavement Analysis and Design Parameters
The pavement design parameters we used in our analyses are summarized below. The parameters we used
for our analysis are based on guidance and data from AASHTO “Guide for Design of Pavement Structures”
1993 (AASHTO), WSDOT “Pavement Policy” September 2018, and the results from the FWD testing.
4.2.1. Pavement Design Criteria
■ Standard Deviation = 0.45 (AASHTO)
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File No. 22247-004-02
■ Reliability = 85 percent (WSDOT)
■ Initial Serviceability = 4.2 (AASHTO)
■ Terminal Serviceability = 2.5 (AASHTO)
4.2.2. Subgrade and Material Strength Coefficients
■ Subgrade Modulus (Mr) is based on 1st Quartile of FWD Data and proposed subgrade rehabilitation
Segment 1 – 9,000 pounds per square inch (psi)
Segment 2 – 11,900 psi
Segment 3 – 8,500 psi*
■ Crushed Surfacing Base Course (Mr) = 30,000 psi (WSDOT)
■ Crushed Surfacing Base Course Structural Coefficient = 0.13 (WSDOT)
■ New Asphalt Structural Coefficient =0.45 (WSDOT)
* Although the observed pavement damage is not directly indicative of subgrade deterioration, the design
Mr was reduced from about 9,500 psi to 8,500 psi in Segment 3 to account for any subgrade damage that
could have occurred after the 2017 FWD testing was performed. We consider this to be conservative.
5.0 PAVEMENT SECTION RECOMMENDATIONS
5.1. Design Approach
We developed a design pavement section in general accordance with AASHTO 1993 “Flexible Pavement
Design Standards” and the design coefficients stated in the previous section. The design pavement section
is based on the assumption that the entire existing pavement section will be removed, the existing subgrade
soils will be evaluated, compacted in place or remediated as necessary, and a new pavement section will
be built on top of the existing or remediated subgrade soils. The design is based on a subgrade modulus
from the lower quartile of FWD data. The weakest sections of subgrade in isolated areas are expected to
be remediated during construction. We also evaluated the design using a subgrade modulus of 2,500 psi,
which is near the lowest value measured in all the FWD data. This was used to estimate the maximum
required overexcavation and subbase thickness.
5.2. Pavement Overlay Considerations and Recommendations
We evaluated the practicality of overlaying the section of Weyerhaeuser Way between South 323rd Street
and South 320th Steet considering the current pavement condition, existing design section, and proposed
traffic loading. It is our opinion based on that assessment that an overlay of the travel lanes would not be
practical. The amount of additional asphalt required to provide an equivalent section would make matching
grades with the existing curbs difficult.
A section of the center turn lane could be rehabilitated with an overlay provided it is practical with
construction staging. The center turn lane was observed to have significantly less damage than the travel
lanes and is expected to have significantly less heavy truck traffic over the design life of the pavement. An
overlay would not be appropriate in the center turn lane used for queuing at the South 320th Street
intersection, the northernmost 350 feet of the roadway.
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If an overlay in this area will be used, we recommend a minimum overlay thickness of 2 inches of asphalt.
This can be added to the existing asphalt or the top of the existing asphalt can be ground down to facilitate
matching existing grades.
5.3. Recommended Pavement Sections
5.3.1. Segment 1 –South 336th Street Roundabout to Midpoint of the Woodbridge Business Park Development
■ 5.5 inches (0.46 foot) Asphalt Concrete (Minimum Class ½ inch PG58H-22; WSDOT Standard
Specifications 5-04, 9-02, and 9-03).
■ 11 inches (0.92 foot) of Crushed Surfacing Base Course (WSDOT Standard Specification 9-03.9(3))
compacted to 95 percent of maximum dry density (MDD) per ASTM International (ASTM) D 1557 or to
a firm and unyielding condition as indicated by proof-roll observed by GeoEngineers. Contractor may
choose to use CSTC in the upper 2 inches of the section to assist with grading.
■ 0 to 24 inches (0 to 2 feet) of Aggregate for Gravel Base (WSDOT Standard Specification 9-03.10)
compacted to 95 percent of MDD per ASTM D 1557 or to a firm and unyielding condition as indicated
by proof-roll observed by GeoEngineers.
■ Firm and unyielding subgrade confirmed by proof-roll and/or observation by GeoEngineers.
5.3.2. Segment 2 –Midpoint of the Woodbridge Business Park Development to South 323rd Street
■ 5.5 inches (0.46 foot) Asphalt Concrete (Minimum Class ½ inch PG58H-22; WSDOT Standard
Specifications 5-04, 9-02, and 9-03).
■ 8 inches (0.67 foot) of Crushed Surfacing Base Course (WSDOT Standard Specification 9-03.9(3))
compacted to 95 percent of MDD per ASTM D 1557 or to a firm and unyielding condition as indicated
by proof-roll observed by GeoEngineers. Contractor may choose to use CSTC in the upper 2 inches of
the section to assist with grading.
■ 0 to 24 inches (0 to 2 feet) of Aggregate for Gravel Base (WSDOT Standard Specification 9-03.10)
compacted to 95 percent of MDD per ASTM D 1557 or to a firm and unyielding condition as indicated
by proof-roll observed by GeoEngineers.
■ Firm and unyielding subgrade confirmed by proof-roll and/or observation by GeoEngineers.
5.3.3. Segment 3 – South 323rd Street to South 320th Street
■ 5.5 inches (0.46 foot) Asphalt Concrete (Minimum Class ½ inch PG58H-22; WSDOT Standard
Specifications 5-04, 9-02, and 9-03).
■ 11 inches (0.92 foot) of Crushed Surfacing Base Course (WSDOT Standard Specification 9-03.9(3))
compacted to 95 percent of MDD per ASTM D 1557 or to a firm and unyielding condition as indicated
by proof-roll observed by GeoEngineers. Contractor may choose to use CSTC in the upper 2 inches of
the section to assist with grading.
■ 0 to 24 inches (0 to 2 feet) of Aggregate for Gravel Base (WSDOT Standard Specification 9-03.10)
compacted to 95 percent of MDD per ASTM D 1557 or to a firm and unyielding condition as indicated
by proof-roll observed by GeoEngineers.
■ Firm and unyielding subgrade confirmed by proof-roll and/or observation by GeoEngineers.
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File No. 22247-004-02
Please note that the design segment designations or limits are approximate. Adjusting the limits by a few
hundred feet to facilitate construction staging and provide consistency with the construction stages is
appropriate and will likely result in more efficient construction and, therefore, a better final product.
5.4. Construction Recommendations
The subgrade soils must be thoroughly compacted to a uniformly firm and unyielding condition prior to
constructing the roadway section or placing structural fill. We recommend that subgrades be proof-rolled
or probed, as appropriate, to identify areas of yielding or soft soil. Proof-rolling should be accomplished with
a heavy piece of wheeled construction equipment such as a loaded dump truck or grader. Probing should
be used if proof-rolling is not possible due to site constraints.
If soft or otherwise unsuitable areas are revealed during proof-rolling or probing that cannot be compacted
to a stable and uniformly firm condition, we recommend that: (1) the unsuitable soils be scarified (e.g., with
a ripper or farmer’s disc), aerated and recompacted; or (2) the unsuitable soils be overexcavated and
replaced with compacted aggregate for gravel base, effectively increasing the pavement section.
Overexcavation should extend until uniformly firm soils are encountered as determined by a representative
from our firm.
In our opinion, and based on our analysis and design, overexcavation deeper than about 2 feet is not
required. If a somewhat firm soil (consistent with a Mr of 2,500 psi) is not encountered after 2 feet of
excavation below the subgrade, we recommend that the overexcavation be filled with a crushed aggregate
such as crushed rock base course. If the soil at the base of the overexcavation is wet and compaction
cannot be achieved, we recommend that the overexcavation be filled with Permeable Ballast (WSDOT
Standard Specification 9-03.9(2)).
In our opinion recycled aggregate materials, either derived on site from excavated and processed pavement
sections or imported, are suitable for use as pavement aggregates. All recycled aggregate materials must
meet the gradation and performance specifications for the required aggregates and the WSDOT
specification for Recycled Material (WSDOT Standard Specification 9-03.21).
6.0 LIMITATIONS
We have prepared this report for Federal Way Campus, LLC, for the Weyerhaeuser Way South, 320th Street
to 336th Street Woodbridge Business Park Project located in Federal Way, Washington. Federal Way
Campus, LLC, may distribute copies of this report to owner’s authorized agents and regulatory agencies as
may be required for the Project.
Within the limitations of scope, schedule and budget, our services have been executed in accordance with
generally accepted practices for geotechnical engineering in this area at the time this report was prepared.
The conclusions, recommendations, and opinions presented in this report are based on our professional
knowledge, judgment and experience. No warranty, express or implied, applies to the services or this report.
Please refer to Appendix B titled “Report Limitations and Guidelines for Use” for additional information
pertaining to use of this report.
µ
SITE
Vicinity Map
Figure 1
Weyerhaeuser Way Pavement EvaluationFederal Way, Washington
2,000 2,0000
Feet
Data Source: Mapbox Open Street Map, 2017
Not es :1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication.
Projection: NAD 1983 UTM Zone 10N
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32nd Ave SI5 SouthboundI5 NorthboundNorth Lake
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Site Plan
Weyerhaeuser Way Pavement EvaluationFederal Way, Washington
Figure 2
µ400 0 400
Feet
Legend
FWD Analysis Point
!(Northbound Lane
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E
Approximate Project Stationing as Established by Pavement Services, Inc.
Notes:1. The locations of all features shown are approximate.2. This drawing is for information purposes. It is intended to assist in showing features discussed in an attached document. GeoEngineers, Inc. cannot guarantee the accuracy and content of electronic files. The master file is stored by GeoEngineers, Inc. and will serve as the official record of this communication.
Projection: NAD 1983 StatePlane Washington North FIPS 4601 Feet
P:\22\22247004\GIS\MXDs\2224700400_F02_NorthSitePlan.mxd Date Exported: 07/28/17 by cchelf
Data Source: Aerial from King County 2015
10+00
APPENDIX A
FWD Results and Data
Project 17019
Index No. Test Station Lane
Corrected
Subgrade Mr, psi
Pavement Modulus
(Ep), psi SNeff
34 50+25 NB 9,004 513,396 2.16
35 52+27 NB 10,920 622,304 2.31
36 54+26 NB 8,031 606,008 2.28
37 56+30 NB 10,947 303,913 1.82
39 60+25 NB 10,656 505,613 2.15
41 64+25 NB 10,142 478,084 2.11
42 66+25 NB 16,462 551,108 2.21
44 70+25 NB 15,534 732,925 2.43
45 72+25 NB 15,319 837,291 2.54
47 76+26 NB 13,701 505,035 2.15
49 80+26 NB 14,609 450,290 2.07
50 82+25 NB 12,323 584,581 2.26
52 86+16 NB 10,656 608,479 2.29
53 88+25 NB 6,808 408,587 2.00
54 90+25 NB 10,430 395,344 1.98
55 92+25 NB 11,702 199,132 1.58
56 94+25 NB 11,169 306,771 1.82
59 51+17 SB 6,546 235,012 1.67
60 53+27 SB 10,813 307,866 1.82
61 55+24 SB 9,427 401,870 1.99
62 57+22 SB 11,860 306,771 1.82
64 61+24 SB 11,733 401,870 1.99
66 65+25 SB 16,839 401,870 1.99
68 69+24 SB 8,877 446,652 2.06
69 71+25 SB 14,560 438,917 2.05
70 73+25 SB 13,451 494,628 2.14
72 77+22 SB 16,524 450,290 2.07
73 79+21 SB 16,903 558,560 2.22
74 81+25 SB 15,645 307,866 1.82
75 83+25 SB 11,765 425,009 2.03
76 85+25 SB 14,324 413,797 2.01
77 87+22 SB 12,393 279,702 1.77
78 89+35 SB 8,967 301,862 1.81
79 91+25 SB 11,519 185,560 1.54
80 93+25 SB 13,787 310,700 1.83
81 95+24 SB 11,459 280,811 1.77
Appendix A
FWD Results and Data
320th Street to 336th Street Woodbridge Business Park
Federal Way, Washington
APPENDIX B
Report Limitations and Guidelines for Use
August 16, 2021| Page B-1
File No. 22247-004-02
APPENDIX B
REPORT LIMITATIONS AND GUIDELINES FOR USE1
This appendix provides information to help you manage your risks with respect to the use of this report.
Read These Provisions Closely
It is important to recognize that the geoscience practices (geotechnical engineering, geology and
environmental science) rely on professional judgment and opinion to a greater extent than other
engineering and natural science disciplines, where more precise and/or readily observable data may exist.
To help clients better understand how this difference pertains to our services, GeoEngineers includes the
following explanatory “limitations” provisions in its reports. Please confer with GeoEngineers if you need to
know more how these “Report Limitations and Guidelines for Use” apply to your project or site.
Geotechnical Services are Performed for Specific Purposes, Persons and Projects
This report has been prepared for Federal Way Campus, LLC and for the Project(s) specifically identified in
the report. The information contained herein is not applicable to other sites or projects.
GeoEngineers structures its services to meet the specific needs of its clients. No party other than the party
to whom this report is addressed may rely on the product of our services unless we agree to such reliance
in advance and in writing. Within the limitations of the agreed scope of services for the Project, and its
schedule and budget, our services have been executed in accordance with our Agreement with Federal Way
Campus, LLC dated April 30, 2021 and signed August 9, 2021 and generally accepted geotechnical
practices in this area at the time this report was prepared. We do not authorize, and will not be responsible
for, the use of this report for any purposes or projects other than those identified in the report.
A Geotechnical Engineering or Geologic Report is based on a Unique Set of Project-Specific
Factors
This report has been prepared for the proposed Weyerhaeuser Way Improvement project in support of the
Weyerhaeuser Way South, 320th Street to 336th Street Woodbridge Business Park Project Washington.
GeoEngineers considered a number of unique, project-specific factors when establishing the scope of
services for this project and report. Unless GeoEngineers specifically indicates otherwise, it is important not
to rely on this report if it was:
■ not prepared for you,
■ not prepared for your project,
■ not prepared for the specific site explored, or
■ completed before important project changes were made.
1 Developed based on material provided by ASFE, Professional Firms Practicing in the Geosciences; www.asfe.org.
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For example, changes that can affect the applicability of this report include those that affect:
■ the function of the proposed structure;
■ elevation, configuration, location, orientation or weight of the proposed structure;
■ composition of the design team; or
■ project ownership.
If changes occur after the date of this report, GeoEngineers cannot be responsible for any consequences
of such changes in relation to this report unless we have been given the opportunity to review our
interpretations and recommendations. Based on that review, we can provide written modifications or
confirmation, as appropriate.
Environmental Concerns are Not Covered
Unless environmental services were specifically included in our scope of services, this report does not
provide any environmental findings, conclusions, or recommendations, including but not limited to, the
likelihood of encountering underground storage tanks or regulated contaminants.
Subsurface Conditions Can Change
This geotechnical or geologic report is based on conditions that existed at the time the study was performed.
The findings and conclusions of this report may be affected by the passage of time, by man-made events
such as construction on or adjacent to the site, new information or technology that becomes available
subsequent to the report date, or by natural events such as floods, earthquakes, slope instability or
groundwater fluctuations. If more than a few months have passed since issuance of our report or work
product, or if any of the described events may have occurred, please contact GeoEngineers before applying
this report for its intended purpose so that we may evaluate whether changed conditions affect the
continued reliability or applicability of our conclusions and recommendations.
Geotechnical and Geologic Findings are Professional Opinions
Our interpretations of subsurface conditions are based on field observations from widely spaced sampling
locations at the site. Site exploration identifies the specific subsurface conditions only at those points where
subsurface tests are conducted or samples are taken. GeoEngineers reviewed field and laboratory data
and then applied its professional judgment to render an informed opinion about subsurface conditions at
other locations. Actual subsurface conditions may differ, sometimes significantly, from the opinions
presented in this report. Our report, conclusions and interpretations are not a warranty of the actual
subsurface conditions.
Geotechnical Engineering Report Recommendations are Not Final
We have developed the following recommendations based on data gathered from subsurface
investigation(s). These investigations sample just a small percentage of a site to create a snapshot of the
subsurface conditions elsewhere on the site. Such sampling on its own cannot provide a complete and
accurate view of subsurface conditions for the entire site. Therefore, the recommendations included in this
report are preliminary and should not be considered final. GeoEngineers’ recommendations can be
finalized only by observing actual subsurface conditions revealed during construction. GeoEngineers
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cannot assume responsibility or liability for the recommendations in this report if we do not perform
construction observation.
We recommend that you allow sufficient monitoring, testing and consultation during construction by
GeoEngineers to confirm that the conditions encountered are consistent with those indicated by the
explorations, to provide recommendations for design changes if the conditions revealed during the work
differ from those anticipated, and to evaluate whether earthwork activities are completed in accordance
with our recommendations. Retaining GeoEngineers for construction observation for this project is the most
effective means of managing the risks associated with unanticipated conditions. If another party performs
field observation and confirms our expectations, the other party must take full responsibility for both the
observations and recommendations. Please note, however, that another party would lack our project-
specific knowledge and resources.
A Geotechnical Engineering or Geologic Report Could Be Subject to Misinterpretation
Misinterpretation of this report by members of the design team or by contractors can result in costly
problems. GeoEngineers can help reduce the risks of misinterpretation by conferring with appropriate
members of the design team after submitting the report, reviewing pertinent elements of the design team’s
plans and specifications, participating in pre-bid and preconstruction conferences, and providing
construction observation.
Do Not Redraw the Exploration Logs
Geotechnical engineers and geologists prepare final boring and testing logs based upon their interpretation
of field logs and laboratory data. The logs included in a geotechnical engineering or geologic report should
never be redrawn for inclusion in architectural or other design drawings. Photographic or electronic
reproduction is acceptable, but separating logs from the report can create a risk of misinterpretation.
Give Contractors a Complete Report and Guidance
To help reduce the risk of problems associated with unanticipated subsurface conditions, GeoEngineers
recommends giving contractors the complete geotechnical engineering or geologic report, including these
“Report Limitations and Guidelines for Use.” When providing the report, you should preface it with a clearly
written letter of transmittal that:
■ advises contractors that the report was not prepared for purposes of bid development and that its
accuracy is limited; and
■ encourages contractors to confer with GeoEngineers and/or to conduct additional study to obtain the
specific types of information they need or prefer.
Contractors are Responsible for Site Safety on Their Own Construction Projects
Our geotechnical recommendations are not intended to direct the contractor’s procedures, methods,
schedule or management of the work site. The contractor is solely responsible for job site safety and for
managing construction operations to minimize risks to on-site personnel and adjacent properties.
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Biological Pollutants
GeoEngineers’ Scope of Work specifically excludes the investigation, detection, prevention or assessment
of the presence of Biological Pollutants. Accordingly, this report does not include any interpretations,
recommendations, findings or conclusions regarding the detecting, assessing, preventing or abating of
Biological Pollutants, and no conclusions or inferences should be drawn regarding Biological Pollutants as
they may relate to this project. The term “Biological Pollutants” includes, but is not limited to, molds, fungi,
spores, bacteria and viruses, and/or any of their byproducts.
A Client that desires these specialized services is advised to obtain them from a consultant who offers
services in this specialized field.