22-100593-CO-9th Avenue South Industrial Revised Retaining Wall Designs-02-23-2022-V2August 17, 2021
Revised December 14, 2021
Project No. T-8425
Mr. Dustin Highland
Smith Brothers Farms
c/o KG Investments
11225 – Southeast 6th Street, Suite 215
Bellevue, Washington 98004
Subject: Retaining Wall Designs
9th Avenue South Industrial
34520 – 9th Avenue South
Federal Way, Washington
Reference: Geotechnical Report, 9th Avenue South Industrial, 34520 – 9th Avenue South, Federal Way,
Washington, Project No. T-8425, prepared by Terra Associates, Inc., dated May 25, 2021
Dear Mr. Highland:
As requested, we have prepared designs for construction of the project’s Ultrablock retaining walls. This letter
presents the results of our analyses and provides recommendations for construction.
Based on a review of the “Grading and Drainage plan” prepared by Barghausen Consulting Engineers, dated
November 4, 2021, there are two walls planned for the project. A cut gravity Ultrablock wall is planned in the
northeast corner of the project and will support the vertical grade transition between the property and adjacent
property to the east. The wall has a maximum height of 5 feet with a 2:1 (Horizontal: Vertical) or flatter
backslope and horizontal frontslope. The second wall is a fill wall located along a portion of the southern and
western property lines and will support the vertical grade transition between the project and adjacent property to
the south and 9th Avenue South to the west. The wall has a maximum height of 15 feet with a 2:1 (Horizontal:
Vertical) or flatter frontslope and horizontal backslope.
Soil conditions used in the design of the Ultrablock wall were based on information contained in the referenced
report. Our Ultrablock wall designs were completed using Excel. All analyses yielded acceptable factors of
safety for both static and seismic cases. Details showing cut Ultrablock walls are shown on attached Figure 1.
12220 113th Avenue NE, Ste. 130, Kirkland, Washington 98034
Phone (425) 821‐7777 • Fax (425) 821‐4334
12-14-2021
GENERAL NOTES1) REFER TO CIVIL GRADING PLANS FOR WALL ALIGNMENTS ANDELEVATIONS.2) ULTRA BLOCK ® WALL ASSEMBLY TO BE COMPLETED PERMANUFACTURERS SPECIFICATIONS.4'(MAX.)5.25'(MAX.)1616ULTRA BLOCK STANDARD UNIT2.5'X2.5'X5'12" WIDE DRAIN COLUM 3/4"WASHED ROCK <2% FINES4" PERFORATED DRAIN PIPESURROUNDED BY 3" OF DRAINROCK (MIN.)TAKEN TO APPROVEDPOINT OF DISCHARGEFIRM AND STABLE SUBGRADETO BE VERIFIED BY GEOTECHNICAL ENGINEER4" THICK (MIN.) 5/8" CRUSHED ROCK LEVELING PADFIRM AND STABLE SUBGRADETO BE VERIFIED BY GEOTECHNICAL ENGINEER4" THICK (MIN.) 5/8" CRUSHED ROCK LEVELING PAD4" PERFORATED DRAIN PIPESURROUNDED BY 3" OF DRAINROCK (MIN.)TAKEN TO APPROVEDPOINT OF DISCHARGE12" WIDE DRAIN COLUM 3/4"WASHED ROCK <2% FINES1'1'DENSE NATIVE SOILS5' ULTRA-BLOCK WALLNOT TO SCALE6.25' ULTRA-BLOCK WALLNOT TO SCALEULTRA BLOCK STANDARD UNIT2.5'X2.5'X5'ULTRA BLOCK HALF CAP UNIT1.25'X2.5'X5'®®®®®ULTRA BLOCK FULL CAP UNIT2.5'X2.5'X5'®1'(MIN.)FENCE/RAIL WHERE REQUIREDFENCE/RAIL WHERE REQUIRED12(MAX)12(MAX)DENSE NATIVE SOILS1'(MIN.)Consultants in Geotechnical EngineeringTerraAssociates, Inc.Geology andEnvironmental Earth SciencesULTRABLOCK WALL DETAILSFigure 1Proj.No.T-8425Date: DEC 2021FEDERAL WAY, WASHINGTON9TH AVE INDUSTRIAL
5'(MAX.)FIRM AND STABLE SUBGRADETO BE VERIFIED BY GEOTECHNICAL ENGINEER4" THICK (MIN.) 5/8" CRUSHED ROCK LEVELING PAD4" PERFORATED DRAIN PIPESURROUNDED BY 3" OF DRAINROCK (MIN.)TAKEN TO APPROVEDPOINT OF DISCHARGE12" WIDE DRAIN COLUM 3/4"WASHED ROCK <2% FINESSTRUCTURAL BACKFILLPER GEOTECHNICAL REPORT5' ULTRABLOCK WALLNOT TO SCALE162.5'(MAX.)16FIRM AND STABLE SUBGRADETO BE VERIFIED BY GEOTECHNICAL ENGINEER4" THICK (MIN.) 5/8" CRUSHED ROCK LEVELING PAD4" PERFORATED DRAIN PIPESURROUNDED BY 3" OF DRAINROCK (MIN.)TAKEN TO APPROVEDPOINT OF DISCHARGE12" WIDE DRAIN COLUM 3/4"WASHED ROCK <2% FINESSTRUCTURAL BACKFILLPER GEOTECHNICAL REPORT2.5' ULTRABLOCK WALLNOT TO SCALEFENCE/RAIL WHEREREQUIREDFENCE/RAIL WHEREREQUIRED1' COMPACTED STRUCTURAL FILL ABOVE DRAIN COLUMN1' COMPACTED STRUCTURAL FILL ABOVE DRAIN COLUMNULTRA BLOCK STANDARD UNIT2.5'X2.5'X5' (TYP.)ULTRA BLOCK STANDARD UNIT2.5'X2.5'X5' (TYP.)2.5' (MIN.)12 (MAX.)2.5' (MIN.)12 (MAX.)Consultants in Geotechnical EngineeringTerraAssociates, Inc.Geology andEnvironmental Earth Sciences2.5' - 5' ULTRABLOCK WALL DETAILSFigure 2Proj.No.T-8425Date: DEC 2021FEDERAL WAY, WASHINGTON9TH AVE INDUSTRIAL
10'(MAX.)FIRM AND STABLE SUBGRADETO BE VERIFIED BY GEOTECHNICAL ENGINEER4" THICK (MIN.) 5/8" CRUSHED ROCK LEVELING PAD4" PERFORATED DRAIN PIPESURROUNDED BY 3" OF DRAINROCK (MIN.)TAKEN TO APPROVEDPOINT OF DISCHARGE12" WIDE DRAIN COLUM 3/4"WASHED ROCK <2% FINES10' ULTRABLOCK WALLNOT TO SCALE16FENCE/RAIL WHEREREQUIRED1' COMPACTED STRUCTURAL FILL ABOVE DRAIN COLUMNULTRA BLOCK STANDARD UNIT2.5'X2.5'X5' (TYP.)7.5'(MAX.)FIRM ANDSTABLE SUBGRADETO BE VERIFIED BYGEOTECHNICAL ENGINEER4" THICK (MIN.) 5/8" CRUSHED ROCK LEVELING PAD4" PERFORATED DRAIN PIPESURROUNDED BY 3" OF DRAINROCK (MIN.)TAKEN TO APPROVEDPOINT OF DISCHARGE12" WIDE DRAIN COLUM 3/4"WASHED ROCK <2% FINESSTRUCTURAL BACKFILLPER GEOTECHNICAL REPORT7.5' ULTRABLOCK WALLNOT TO SCALE16FENCE/RAIL WHEREREQUIRED1' COMPACTED STRUCTURAL FILL ABOVE DRAIN COLUMNULTRA BLOCK STANDARD UNIT2.5'X2.5'X5' (TYP.)2.5' (MIN.)12 (MAX.)2.5' (MIN.)12 (MAX.)STRUCTURAL BACKFILLPER GEOTECHNICAL REPORTConsultants in Geotechnical EngineeringTerraAssociates, Inc.Geology andEnvironmental Earth Sciences7.5' - 10' ULTRABLOCK WALL DETAILSFigure 3Proj.No.T-8425Date: DEC 2021FEDERAL WAY, WASHINGTON9TH AVE INDUSTRIAL
12.5'(MAX.)FIRM AND STABLE SUBGRADETO BE VERIFIED BY GEOTECHNICAL ENGINEER4" THICK (MIN.) 5/8" CRUSHED ROCK LEVELING PAD4" PERFORATED DRAIN PIPESURROUNDED BY 3" OF DRAINROCK (MIN.)TAKEN TO APPROVEDPOINT OF DISCHARGE12" WIDE DRAIN COLUM 3/4"WASHED ROCK <2% FINESSTRUCTURAL BACKFILLPER GEOTECHNICAL REPORT12.5' ULTRABLOCK WALLNOT TO SCALE16FENCE/RAIL WHEREREQUIRED1' COMPACTED STRUCTURAL FILL ABOVE DRAIN COLUMNULTRA BLOCK STANDARD UNIT2.5'X2.5'X5' (TYP.)2.5' (MIN.)12 (MAX.)Consultants in Geotechnical EngineeringTerraAssociates, Inc.Geology andEnvironmental Earth Sciences12.5' ULTRABLOCK WALL DETAILSFigure 4Proj.No.T-8425Date: DEC 2021FEDERAL WAY, WASHINGTON9TH AVE INDUSTRIAL
15'(MAX.)STRUCTURAL BACKFILLPER GEOTECHNICAL REPORT164" PERFORATED DRAIN PIPESURROUNDED BY 3" OF DRAINROCK (MIN.)TAKEN TO APPROVEDPOINT OF DISCHARGE2.5' (MIN.)FENCE/RAIL WHEREREQUIRED1' COMPACTED STRUCTURAL FILL ABOVE DRAIN COLUMNULTRA BLOCK STANDARD UNIT2.5'X2.5'X5' (TYP.)12" WIDE DRAIN COLUM 3/4"WASHED ROCK <2% FINES12 (MAX.)15' ULTRABLOCK WALLNOT TO SCALEConsultants in Geotechnical EngineeringTerraAssociates, Inc.Geology andEnvironmental Earth Sciences15' ULTRABLOCK WALL DETAILSFigure 5Proj.No.T-8425Date: DEC 2021FEDERAL WAY, WASHINGTON9TH AVE INDUSTRIAL
DESIGN CALCULATIONS – CUT GRAVITY ULTRABLOCK RETAINING WALLS
Wall Geometry
Enter Wall Height (Hw): 5.00 Gravity Ultrablock Cut Walls
Enter Depth of Wall Below Front Grade (Dw): 1.25 9th Ave South Industrial
Enter Wall Backslope Angle (degrees): 26.00 Federal Way, Washington
Enter Height of Slope Above Top of Wall: 6.00 T-8425
Enter Horizontal Distance Beyond Slope Crest: 20.00
Enter Slope Angle in Front of Wall (degrees): 0.00
Enter Height of Slope Below Wall (Hb): 0.00
Distance From Back of Wall to Beginning of Surcharge 0.00
Horizontal Extent of Surcharge: 0.00
Surcharge Magnitude (psf): 250.00
Enter Block or Gabion Height (feet) 2.50
Enter Block or Gabion Depth (feet) 2.50
Enter Unit weight of block (pcf) 140.00
Number of Units in Wall Height 2.00
Number of Units in Wall Depth 1.00
Base Width (feet) 2.50
Height of First Back Column (feet) 0.00
Height of Second Back Column (feet) 0.00 Wall Stability Summary
Height of Third Back Column (feet) 0.00 Static Seismic
Enter Wall Batter (degrees) 9.46 Sliding Safety Factor = 16.71 1.41
x-component 0.16 Overturning at Wall Base Safety Factor = 17.63 1.48
Y-component 0.99 Overturning One Unit Up Safety Factor = 20.57 3.59
Overturning Two Units Up Safety Factor =
Soil Parameters
Foundation Soil
Soil Unit Weight (pcf) 125.00
Friction Angle (degrees) 38.00
Cohesion (psf) 0.00 Vertical Load (lbs.) 1750.00
Wall Friction Angle 25.33 Resultant Location (x) 1.55
Ka (coulomb) 0.31 0.48 B/6 0.42
eccentricity (e)= -0.30
Backfill Soil Zone
Soil Unit Weight (pcf) 125.00 q max (psf) 194.92
Friction Angle (degrees) 38.00 q min (psf) 1205.08
Cohesion (psf) 0.00
Wall Friction Angle 24.00 Ultimate Bearing Capacity
Ka (coulomb) 0.313 0.47 Nq 48.93
Nc 61.35
Seismic Acceleration 0.28 N gamma 78.02 Vesic
N gamma 56.17 Hansen
q ult. 19837.11
Bearing S.F. 101.77
Bearing Capacity Evaluation
Wall Geometry
Enter Wall Height (Hw): 6.25 Gravity Ultrablock Cut Walls
Enter Depth of Wall Below Front Grade (Dw): 1.25 9th Ave South Industrial
Enter Wall Backslope Angle (degrees): 26.00 Federal Way, Washington
Enter Height of Slope Above Top of Wall: 6.00 T-8425
Enter Horizontal Distance Beyond Slope Crest: 20.00
Enter Slope Angle in Front of Wall (degrees): 0.00
Enter Height of Slope Below Wall (Hb): 0.00
Distance From Back of Wall to Beginning of Surcharge 0.00
Horizontal Extent of Surcharge: 0.00
Surcharge Magnitude (psf): 250.00
Enter Block or Gabion Height (feet) 2.50
Enter Block or Gabion Depth (feet) 2.50
Enter Unit weight of block (pcf) 140.00
Number of Units in Wall Height 2.50
Number of Units in Wall Depth 1.00
Base Width (feet) 2.50
Height of First Back Column (feet) 0.00
Height of Second Back Column (feet) 0.00 Wall Stability Summary
Height of Third Back Column (feet) 0.00 Static Seismic
Enter Wall Batter (degrees) 9.46 Sliding Safety Factor = 7.43 1.23
x-component 0.16 Overturning at Wall Base Safety Factor = 6.66 1.11
Y-component 0.99 Overturning One Unit Up Safety Factor = 88.14 2.15
Overturning Two Units Up Safety Factor = 10.91 8.27
Soil Parameters
Foundation Soil
Soil Unit Weight (pcf) 125.00
Friction Angle (degrees) 38.00
Cohesion (psf) 0.00 Vertical Load (lbs.) 2187.50
Wall Friction Angle 25.33 Resultant Location (x) 1.48
Ka (coulomb) 0.31 0.48 B/6 0.42
eccentricity (e)= -0.23
Backfill Soil Zone
Soil Unit Weight (pcf) 125.00 q max (psf) 382.90
Friction Angle (degrees) 38.00 q min (psf) 1367.10
Cohesion (psf) 0.00
Wall Friction Angle 24.00 Ultimate Bearing Capacity
Ka (coulomb) 0.313 0.47 Nq 48.93
Nc 61.35
Seismic Acceleration 0.28 N gamma 78.02 Vesic
N gamma 56.17 Hansen
q ult. 19837.11
Bearing S.F. 51.81
Bearing Capacity Evaluation
DESIGN CALCULATIONS – FILL GRAVITY ULTRABLOCK RETAINING WALLS
Wall Geometry
Enter Wall Height (Hw): 5.00 Gravity Ultra Block Walls
Enter Depth of Wall Below Front Grade (Dw): 2.50 9th Avenue Industrial
Enter Wall Backslope Angle (degrees): 0.00 Federal Way, Washington
Enter Height of Slope Above Top of Wall: 0.00 T-8425
Enter Horizontal Distance Beyond Slope Crest: 0.00
Enter Slope Angle in Front of Wall (degrees): 26.00
Enter Height of Slope Below Wall (Hb): 6.00
Distance From Back of Wall to Beginning of Surcharge: 3.00
Horizontal Extent of Surcharge: 30.00
Surcharge Magnitude (psf): 250.00
Enter Block or Gabion Height (feet) 2.50
Enter Block or Gabion Depth (feet) 2.50
Enter Unit weight of block (pcf) 140.00
Number of Units in Wall Height 2.00
Number of Units in Wall Depth 1.00
Base Width (feet) 2.50
Height of First Back Column (feet) 0.00
Height of Second Back Column (feet) 0.00 Wall Stability Summary
Height of Third Back Column (feet) 0.00 Static Seismic
Enter Wall Batter (degrees) 9.46 Sliding Safety Factor = 2.03 1.59
x-component 0.16 Overturning at Wall Base Safety Factor = 2.41 1.89
Y-component 0.99 Overturning One Unit Up Safety Factor = 5.85 4.90
Overturning Two Units Up Safety Factor =
Overturning Three Units Up Safety Factor =
Overturning Four Units Up Safety Factor =
Overturning Five Units Up Safety Factor =
Overturning Six Units Up Safety Factor =
Overturning Seven Units Up Safety Factor =
Soil Parameters Overturning Eight Units Up Safety Factor =
Foundation Soil
Soil Unit Weight (pcf) 125.00
Friction Angle (degrees) 34.00
Cohesion (psf) 0.00 Vertical Load (lbs.) 1750.00
Wall Friction Angle 22.67 Resultant Location (x) 0.96
Ka (coulomb) 0.25 0.71 B/6 0.42
eccentricity (e)= 0.29
Backfill Soil Zone
Soil Unit Weight (pcf) 125.00 q max (psf) 1181.99
Friction Angle (degrees) 34.00 q min (psf) 218.01
Cohesion (psf) 0.00
Wall Friction Angle 24.00 Ultimate Bearing Capacity
Ka (coulomb) 0.254 0.72 Nq 29.44
Nc 42.16
Seismic Acceleration 0.20 g N gamma 41.06 Vesic
N gamma 28.77 Hansen
q ult. 15616.15
Bearing S.F. 13.21
Bearing Capacity Evaluation
Wall Geometry
Enter Wall Height (Hw): 7.50 Gravity Ultra Block Walls
Enter Depth of Wall Below Front Grade (Dw): 2.50 9th Avenue Industrial
Enter Wall Backslope Angle (degrees): 0.00 Federal Way, Washington
Enter Height of Slope Above Top of Wall: 0.00 T-8425
Enter Horizontal Distance Beyond Slope Crest: 0.00
Enter Slope Angle in Front of Wall (degrees): 26.00
Enter Height of Slope Below Wall (Hb): 6.00
Distance From Back of Wall to Beginning of Surcharge: 3.00
Horizontal Extent of Surcharge: 30.00
Surcharge Magnitude (psf): 250.00
Enter Block or Gabion Height (feet) 2.50
Enter Block or Gabion Depth (feet) 2.50
Enter Unit weight of block (pcf) 140.00
Number of Units in Wall Height 3.00
Number of Units in Wall Depth 2.00
Base Width (feet) 5.00
Height of First Back Column (feet) 2.50
Height of Second Back Column (feet) 0.00 Wall Stability Summary
Height of Third Back Column (feet) 0.00 Static Seismic
Enter Wall Batter (degrees) 9.46 Sliding Safety Factor = 3.07 2.31
x-component 0.16 Overturning at Wall Base Safety Factor = 4.49 3.38
Y-component 0.99 Overturning One Unit Up Safety Factor = 2.41 1.89
Overturning Two Units Up Safety Factor = 5.85 4.90
Overturning Three Units Up Safety Factor =
Overturning Four Units Up Safety Factor =
Overturning Five Units Up Safety Factor =
Overturning Six Units Up Safety Factor =
Overturning Seven Units Up Safety Factor =
Soil Parameters Overturning Eight Units Up Safety Factor =
Foundation Soil
Soil Unit Weight (pcf) 125.00
Friction Angle (degrees) 34.00
Cohesion (psf) 0.00 Vertical Load (lbs.) 5062.50
Wall Friction Angle 22.67 Resultant Location (x) 2.36
Ka (coulomb) 0.25 0.71 B/6 0.83
eccentricity (e)= 0.14
Backfill Soil Zone
Soil Unit Weight (pcf) 125.00 q max (psf) 1182.50
Friction Angle (degrees) 34.00 q min (psf) 842.50
Cohesion (psf) 0.00
Wall Friction Angle 24.00 Ultimate Bearing Capacity
Ka (coulomb) 0.254 0.72 Nq 29.44
Nc 42.16
Seismic Acceleration 0.20 g N gamma 41.06 Vesic
N gamma 28.77 Hansen
q ult. 22032.37
Bearing S.F. 18.63
Bearing Capacity Evaluation
Wall Geometry
Enter Wall Height (Hw): 10.00 Gravity Ultra Block Walls
Enter Depth of Wall Below Front Grade (Dw): 2.50 9th Avenue Industrial
Enter Wall Backslope Angle (degrees): 0.00 Federal Way, Washington
Enter Height of Slope Above Top of Wall: 0.00 T-8425
Enter Horizontal Distance Beyond Slope Crest: 0.00
Enter Slope Angle in Front of Wall (degrees): 26.00
Enter Height of Slope Below Wall (Hb): 6.00
Distance From Back of Wall to Beginning of Surcharge: 3.00
Horizontal Extent of Surcharge: 30.00
Surcharge Magnitude (psf): 250.00
Enter Block or Gabion Height (feet) 2.50
Enter Block or Gabion Depth (feet) 2.50
Enter Unit weight of block (pcf) 140.00
Number of Units in Wall Height 4.00
Number of Units in Wall Depth 2.00
Base Width (feet) 5.00
Height of First Back Column (feet) 5.00
Height of Second Back Column (feet) 0.00 Wall Stability Summary
Height of Third Back Column (feet) 0.00 Static Seismic
Enter Wall Batter (degrees) 9.46 Sliding Safety Factor = 2.54 1.87
x-component 0.16 Overturning at Wall Base Safety Factor = 2.99 2.20
Y-component 0.99 Overturning One Unit Up Safety Factor = 4.49 3.38
Overturning Two Units Up Safety Factor = 2.41 1.89
Overturning Three Units Up Safety Factor = 5.85 4.90
Overturning Four Units Up Safety Factor =
Overturning Five Units Up Safety Factor =
Overturning Six Units Up Safety Factor =
Overturning Seven Units Up Safety Factor =
Soil Parameters Overturning Eight Units Up Safety Factor =
Foundation Soil
Soil Unit Weight (pcf) 125.00
Friction Angle (degrees) 34.00
Cohesion (psf) 0.00 Vertical Load (lbs.) 6812.50
Wall Friction Angle 22.67 Resultant Location (x) 2.17
Ka (coulomb) 0.25 0.71 B/6 0.83
eccentricity (e)= 0.33
Backfill Soil Zone
Soil Unit Weight (pcf) 125.00 q max (psf) 1909.09
Friction Angle (degrees) 34.00 q min (psf) 815.91
Cohesion (psf) 0.00
Wall Friction Angle 24.00 Ultimate Bearing Capacity
Ka (coulomb) 0.254 0.72 Nq 29.44
Nc 42.16
Seismic Acceleration 0.20 g N gamma 41.06 Vesic
N gamma 28.77 Hansen
q ult. 22032.37
Bearing S.F. 11.54
Bearing Capacity Evaluation
Wall Geometry
Enter Wall Height (Hw): 12.50 Gravity Ultra Block Walls
Enter Depth of Wall Below Front Grade (Dw): 2.50 9th Avenue Industrial
Enter Wall Backslope Angle (degrees): 0.00 Federal Way, Washington
Enter Height of Slope Above Top of Wall: 0.00 T-8425
Enter Horizontal Distance Beyond Slope Crest: 0.00
Enter Slope Angle in Front of Wall (degrees): 26.00
Enter Height of Slope Below Wall (Hb): 6.00
Distance From Back of Wall to Beginning of Surcharge: 3.00
Horizontal Extent of Surcharge: 30.00
Surcharge Magnitude (psf): 250.00
Enter Block or Gabion Height (feet) 2.50
Enter Block or Gabion Depth (feet) 2.50
Enter Unit weight of block (pcf) 140.00
Number of Units in Wall Height 5.00
Number of Units in Wall Depth 2.00
Base Width (feet) 5.00
Height of First Back Column (feet) 7.50
Height of Second Back Column (feet) 0.00 Wall Stability Summary
Height of Third Back Column (feet) 0.00 Static Seismic
Enter Wall Batter (degrees) 9.46 Sliding Safety Factor = 2.17 1.57
x-component 0.16 Overturning at Wall Base Safety Factor = 2.17 1.57
Y-component 0.99 Overturning One Unit Up Safety Factor = 2.99 2.20
Overturning Two Units Up Safety Factor = 4.49 3.38
Overturning Three Units Up Safety Factor = 2.41 1.89
Overturning Four Units Up Safety Factor = 5.85 4.90
Overturning Five Units Up Safety Factor =
Overturning Six Units Up Safety Factor =
Overturning Seven Units Up Safety Factor =
Soil Parameters Overturning Eight Units Up Safety Factor =
Foundation Soil
Soil Unit Weight (pcf) 125.00
Friction Angle (degrees) 34.00
Cohesion (psf) 0.00 Vertical Load (lbs.) 8562.50
Wall Friction Angle 22.67 Resultant Location (x) 1.87
Ka (coulomb) 0.25 0.71 B/6 0.83
eccentricity (e)= 0.63
Backfill Soil Zone
Soil Unit Weight (pcf) 125.00 q max (psf) 3003.21
Friction Angle (degrees) 34.00 q min (psf) 421.79
Cohesion (psf) 0.00
Wall Friction Angle 24.00 Ultimate Bearing Capacity
Ka (coulomb) 0.254 0.72 Nq 29.44
Nc 42.16
Seismic Acceleration 0.20 g N gamma 41.06 Vesic
N gamma 28.77 Hansen
q ult. 22032.37
Bearing S.F. 7.34
Bearing Capacity Evaluation
Wall Geometry
Enter Wall Height (Hw): 15.00 Gravity Ultra Block Walls
Enter Depth of Wall Below Front Grade (Dw): 2.50 9th Avenue Industrial
Enter Wall Backslope Angle (degrees): 0.00 Federal Way, Washington
Enter Height of Slope Above Top of Wall: 0.00 T-8425
Enter Horizontal Distance Beyond Slope Crest: 0.00
Enter Slope Angle in Front of Wall (degrees): 26.00
Enter Height of Slope Below Wall (Hb): 6.00
Distance From Back of Wall to Beginning of Surcharge: 3.00
Horizontal Extent of Surcharge: 30.00
Surcharge Magnitude (psf): 250.00
Enter Block or Gabion Height (feet) 2.50
Enter Block or Gabion Depth (feet) 2.50
Enter Unit weight of block (pcf) 140.00
Number of Units in Wall Height 6.00
Number of Units in Wall Depth 2.00
Base Width (feet) 5.00
Height of First Back Column (feet) 10.00
Height of Second Back Column (feet) 0.00 Wall Stability Summary
Height of Third Back Column (feet) 0.00 Static Seismic
Enter Wall Batter (degrees) 9.46 Sliding Safety Factor = 1.89 1.35
x-component 0.16 Overturning at Wall Base Safety Factor = 1.67 1.20
Y-component 0.99 Overturning One Unit Up Safety Factor = 2.17 1.57
Overturning Two Units Up Safety Factor = 2.99 2.20
Overturning Three Units Up Safety Factor = 4.49 3.38
Overturning Four Units Up Safety Factor = 2.41 1.89
Overturning Five Units Up Safety Factor = 5.85 4.90
Overturning Six Units Up Safety Factor =
Overturning Seven Units Up Safety Factor =
Soil Parameters Overturning Eight Units Up Safety Factor =
Foundation Soil
Soil Unit Weight (pcf) 125.00
Friction Angle (degrees) 34.00
Cohesion (psf) 0.00 Vertical Load (lbs.) 10312.50
Wall Friction Angle 22.67 Resultant Location (x) 1.48
Ka (coulomb) 0.25 0.71 B/6 0.83
eccentricity (e)= 1.02
Backfill Soil Zone
Soil Unit Weight (pcf) 125.00 q max (psf) 4583.99
Friction Angle (degrees) 34.00 q min (psf) -458.99
Cohesion (psf) 0.00
Wall Friction Angle 24.00 Ultimate Bearing Capacity
Ka (coulomb) 0.254 0.72 Nq 29.44
Nc 42.16
Seismic Acceleration 0.20 g N gamma 41.06 Vesic
N gamma 28.77 Hansen
q ult. 22032.37
Bearing S.F. 4.81
Bearing Capacity Evaluation
Wall Geometry
Enter Wall Height (Hw): 17.50 Gravity Ultra Block Walls
Enter Depth of Wall Below Front Grade (Dw): 2.50 9th Avenue Industrial
Enter Wall Backslope Angle (degrees): 0.00 Federal Way, Washington
Enter Height of Slope Above Top of Wall: 0.00 T-8425
Enter Horizontal Distance Beyond Slope Crest: 0.00
Enter Slope Angle in Front of Wall (degrees): 26.00
Enter Height of Slope Below Wall (Hb): 6.00
Distance From Back of Wall to Beginning of Surcharge: 3.00
Horizontal Extent of Surcharge: 30.00
Surcharge Magnitude (psf): 250.00
Enter Block or Gabion Height (feet) 2.50
Enter Block or Gabion Depth (feet) 2.50
Enter Unit weight of block (pcf) 140.00
Number of Units in Wall Height 7.00
Number of Units in Wall Depth 3.00
Base Width (feet) 7.50
Height of First Back Column (feet) 12.50
Height of Second Back Column (feet) 5.00 Wall Stability Summary
Height of Third Back Column (feet) 0.00 Static Seismic
Enter Wall Batter (degrees) 9.46 Sliding Safety Factor = 2.46 1.74
x-component 0.16 Overturning at Wall Base Safety Factor = 2.58 1.83
Y-component 0.99 Overturning One Unit Up Safety Factor = 3.24 2.32
Overturning Two Units Up Safety Factor = 2.17 1.57
Overturning Three Units Up Safety Factor = 2.99 2.20
Overturning Four Units Up Safety Factor = 4.49 3.38
Overturning Five Units Up Safety Factor = 2.41 1.89
Overturning Six Units Up Safety Factor = 5.85 4.90
Overturning Seven Units Up Safety Factor =
Soil Parameters Overturning Eight Units Up Safety Factor =
Foundation Soil
Soil Unit Weight (pcf) 125.00
Friction Angle (degrees) 34.00
Cohesion (psf) 0.00 Vertical Load (lbs.) 17718.75
Wall Friction Angle 22.67 Resultant Location (x) 3.10
Ka (coulomb) 0.25 0.71 B/6 1.25
eccentricity (e)= 0.65
Backfill Soil Zone
Soil Unit Weight (pcf) 125.00 q max (psf) 3583.03
Friction Angle (degrees) 34.00 q min (psf) 1141.97
Cohesion (psf) 0.00
Wall Friction Angle 24.00 Ultimate Bearing Capacity
Ka (coulomb) 0.254 0.72 Nq 29.44
Nc 42.16
Seismic Acceleration 0.20 g N gamma 41.06 Vesic
N gamma 28.77 Hansen
q ult. 28448.59
Bearing S.F. 7.94
Bearing Capacity Evaluation