1310 SE EVERETT MALL WAY Geotech Report 2022-10-25

' Darden Restaurants, Inc. September 15,2011 Proposed Olive Garden—Everett,Washington Page 9 of 12 the borings to a depth of 100 feet as permitted by the code. The estimated soil properties were based upon our experience with subsurface conditions in the general site area. Based upon our evaluation, the subsurface conditions within the site are consistent with the characteristics of a Site Class "C" as defined in the building code. The associated USGS-NEHRP (2003) probabilistic ground acceleration values and site coefficients for the general site area were obtained the USGS geohazards web page (http://earthquake.usqs.qov/research/hazmaps/desiqn) and are presented in Table 1 below. Table 1: Ground Motion Values* Mapped MCE Adjusted MCE Design Period Spectral Site Spectral Spectral (sec) Response Coefficients Response Response Acceleration Acceleration Acceleration 0.2 SS 1.208 Fa 1.0 SMS 1.208 Sos 0.805 1.0 S� 0.423 F� 1.377 SM, 0.582 So� 0.388 *2%Probability of Exceedence in 50 years for Latitude 47.9113 and Longitude-122.2147 MCE=Maximum Considered Earthquake The Site Coefficients, Fa and F� presented in the above table were also obtained from the noted USGS webpage, as a function of the site classification and mapped spectral response acceleration at the short (SS) and 1-second (S�) periods. The site is classified as Seismic Design Category D. For Seismic Design Category designations of C, D, E or F, which are contingent on the structures "Seismic Use Group", the code requires an assessment of slope stability, liquefaction potential and surface rupture due to faulting or lateral spreading. Detailed evaluations of these factors were beyond the scope of this study. However, the following table presents a qualitative assessment of these issues considering the site class, the subsurface soil properties, the groundwater elevation and probabilistic ground motions. Table 2: Qualitative Seismic Site Assessments Hazard Relative Risk Comments We reviewed the "Liquefaction Susceptibility Map of Snohomish County, Washington" map prepared by Washington State Department of Natural Liquefaction Low Resources dated September 2004. That map designates the site as within a "very low" potential liquefaction hazard area. Slope Stability Low Based on the relatively flat condition at the site the otential for slo e instabilit is low. Surface Rupture Low No known active faults underlie the site.