2201 100TH ST SW AD SYSTEMS 2022-03-07

GeoTest Services, Inc. April 25,2017 2201 100th Street Southwest, Everett,WA Job No. 17-0186 For structures designed using the seismic design provisions of the 2015 International Building Code, the native soil interpreted to underlie the site within the upper 100 feet classifies as Site Class D, according to 2010 ASCE -7 Standard — Table 20.3-1, Site Class Definitions. The corresponding values for calculating a design response spectrum for the assumed soil profile type is considered appropriate for the site. Please reference the following values for seismic structural design purposes: Conterminous 48 States—2015 International Building Code Zip Code 98204 Central Latitude = 47.908117, Central Longitude = -122.264063 Short Period (0.2 sec) Spectral Acceleration Maximum Considered Earthquake (MCE) Value of SS= 1.444 (g) Site Response Coefficient, Fa= 1.000 (Site Class D) Adjusted spectral response acceleration for Site Class D, SMs = SS x Fa = 1.444 (g) Design spectral response acceleration for Site Class D, SDS = 2/3 x SMs= 0.963 (g) One Second Period (1 sec) Spectral Acceleration Maximum Considered Earthquake (MCE) Value of Si = 0.562 (g) Site Response Coefficient, Fv= 1.500 (Site Class D) Adjusted spectral response acceleration for Site Class D, SM1 = Si x Fv = 0.842 (g) Design spectral response acceleration for Site Class D, SDI = 2/3 x SMi = 0.562 (g) Foundation Support Foundation support for the proposed improvements may be provided by continuous and individual spread footings founded directly on native, weathered or unweathered glacial 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 (if present) and existing 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 with a smooth-drum roller or a similar piece of construction equipment. Once suitable bearing conditions have been confirmed, then foundations can bear directly on the native soils, or the footprints constructed with property 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. It appears that foundations for the new construction will be poured adjacent to the foundations of the existing building. New foundations should be founded at the same grade as, or below, the existing foundations. Proposed building loads for the new foundations should also be similar to or less than the design loads for the existing foundations. For this, the project team Page 7 of 13