1810 104TH ST SE A T AND T WIRELESS ANTENNA 2022-12-02

Geotechnical Engineering REPUrt 1rerracon SN4924—Silver Lake North Cell Tower Everett,Washington October 24, 2014 Terracon Project No. 81145043 water content, etc.) and the loading conditions, among other factors. The soil parameters presented in the tables are intended to be used in the design of drilled shaft foundations at the site assuming soil and groundwater conditions are similar to those encountered during our field exploration. The applicability of these soil parameters for other uses should be discussed with Terracon. Recommended Soil Properties Layer Depth Layer Approx. Effective Friction Angle, Cohesion, (ft) Thickness (ft) Unit Weight of Soil m C (psf) (pcf) 0 to 5 5 125 33 0 5 to 41.5 36.5 130 40 0 The allowable end bearing pressure, skin friction, and constant of horizontal subgrade reaction (nh for granular soils) values are summarized in the following table. The allowable end bearing pressure and compressive skin friction values presented in the table are based on a factor of safety of 2.0. The allowable skin friction uplift values presented in the table are based on a factor of safety of 2.5. Also, the allowable skin friction to resist both vertical downward loads and uplift forces assumes bored shafts having concrete cast in direct contact with adjacent soil (uncased). The contribution of the upper 18 inches of the soil profile to shaft capacities should be neglected due to the potential freeze-thaw, wet-dry cycles and other disturbance in this zone that could further loosen the soil around the foundation. Recommended Design Parameters Ultimate Allowable Constant of Layer Depth Net Allowable Allowable Skin Equivalent Y P Skin End Bearing Friction; Fluid Horizontal eft) a,,,c d Friction; subgrade Pressure Compression d Passive Uplift a reaction Q,(Psf) sd(Psfl s„(Psf) pressure nn,(PCi) 0 to 5 N/R 201 161 424 175 5 to 41.5 21,300 544 435 598 225 a) N/R=not recommended. Minimum recommended shaft length is 10 feet. b) End bearing with tip elevation at noted depth below existing ground surface. c) For shaft diameters greater than 4 feet, reduce Q by a factor of 1.27/13b where Bb is the shaft diameter in meters. d) Neglect soil resistance for the upper 18 inches due to frost action and other disturbance. e) The equivalent fluid passive pressures provided are for the individual layer, and assumes that there are no limitations on lateral deflection. The pressures should be applied as a triangular distribution over one shaft diameter. These are ultimate values with no safety factor applied. Responsive■ Resourceful■ Reliable 6