3535 RIVERFRONT BLVD Geotech Report 2023-02-22

1 September 24, 2018 HWA Project No. 2015-061-21 I I Table 5—Equivalent Fluid Earth Pressures for the Passive Case(Ultimate Values) Equivalent Fluid Earth Pressures—Passive Case Soil Unit Static Seismic Post-Liquefaction Sandy Silt (El. -7.0 ft to 230 pcf(Kp=3.69) 210 pcf(KPE=3.34) 72 pcf(Kp=1.15) El. -12.0 ft) I Above El. -37 ft=80 pcf Sand Alluvium (Kp=1.28) 230 pcf(Kp=3.69) 210 pcf(KPE=3.34) (Below El. -12 ft) Below El. -37ft=230 pcf I (Kp=3.69) Shore Armor: Above GWT=210 pcf Above GWT= 180 pcf Above GWT=210 pcf I (2H:1V)slope gradient in front Below GWT= 105 pcf Below GWT=90 pcf Below GWT= 105 pcf of wall (Kp= 1.68) (KPE= 1.44) (Kp= 1.68) I I For other walls that may extend below grade on site and support unbalanced earth forces, the above parameters may be employed for the appropriate soil unit in contact with the walls; likely to be Old Fill or more recently placed fill materials. Any new fill to be placed behind and in I close proximity of the sheet pile wall should be considered as surcharge loading and the lateral earth pressure exerted on the wall should be taken as the in-place unit weight of the fill times the earth pressure coefficient of the soil unit in contact with the wall. Temporary equipment loads I and permanent foundation loads that may exert a pressure on the wall should also be taken into account in wall design, and their pressure contribution should be determined on a case specific basis. IThe equivalent fluid pressures for wall design under seismic conditions include combined static soil loading and seismic loading increment. These are ultimate or non-factored values and the I seismic load increment is represented by the net difference between the static and seismic cases provided. The seismic increment may be multiplied by a load factor of 1.0, bearing in mind that the incremental seismic value is also linearly variable with depth (i.e. triangular distribution). IWith regard to the passive resistance provided by shore armor, the gradient or inclination of slope in front of the wall has a very substantial effect (reduction for negative gradient) on the I value that may be relied upon for design purposes. This is most pronounced for seismic conditions. For the proposed river bank slope gradient of 2H:1 V in front of the wall, the recommended equivalent fluid pressures are provided in Table 5. These values are based on an assumed bulk unit weight of 125 pcf for the rip rap and a friction angle of 40 degrees, which is Final Geotechnical Report-3-Acre Park.docx 23 HWA GeoSciences Inc.