3313 OAKES AVE 2020-07-14 - Laserfiche WebLink

GeoTest Services,Inc. December 9,2016 3313 Oakes Avenue,Everett,WA Job No. 16-0659 Please reference the following values for seismic structural design purposes: Conterminous 48 States—2015 International Building Code Zip Code 98201 Central Latitude = 47.97341, Central Longitude = -122.20387 Short Period (0.2 sec) Spectral Acceleration Maximum Considered Earthquake (MCE) Value of Ss= 1.322 (g) Site Response Coefficient, Fa= 1.000 (Site Class C) Adjusted spectral response acceleration for Site Class C, SMS = Ss Fa = 1.322 (g) Design spectral response acceleration for Site Class C, SDS = 2/3 x SMs= 0.882 (g) One Second Period (1 sec) Spectral Acceleration Maximum Considered Earthquake (MCE) Value of S1 = 0.502 (g) Site Response Coefficient, Fv= 1.300 (Site Class C) Adjusted spectral response acceleration for Site Class C, Styli = S1 x Fv = 0.653 (g) Design spectral response acceleration for Site Class C, Sol = 2/3 x SM1 = 0.435 (g) Conventional Foundation Support and Settlement Foundation support for the proposed buildings may be provided by continuous or isolated spread footings founded on the native, weathered or unweathered till soils, or on compacted, structural fill placed over competent, native soils. We recommend that qualified geotechnical personnel confirm that suitable bearing conditions have been reached prior to placement of structural fill or foundation formwork. To provide proper support, we recommend that existing topsoil and fill be removed from beneath the building foundation areas down to the native soils. As discussed previously, dense, unweathered soils are unlikely to require much preparation. However, if footings or structural fill will be placed atop the native, near-surface weathered soils, the surface should be compacted to a firm and unyielding condition. Once suitable bearing conditions have been confirmed, then foundations can bear directly on the native soils, or on properly compacted structural fill as described elsewhere in this report. Continuous and isolated spread footings should be founded a minimum of 18 inches below the lowest adjacent final grade for freeze/thaw protection. The footings should be sized in accordance with the structural engineer's prescribed design criteria and seismic considerations. Allowable Bearing Capacity Assuming the above foundation support criteria are satisfied, continuous or isolated spread footings may be proportioned using a maximum net allowable soil bearing pressure of 2,500 pounds per square foot (psf) for footings prepared directly on properly prepared, firm and unyielding native soil; or on compacted structural fill placed over competent native soil. The term "net allowable bearing pressure" refers to the pressure that can be imposed on the soil at foundation level resulting from the total of all dead plus live loads, exclusive of Page 8 of 17