10312 EVERGREEN WAY SONIC Geotech Report 2023-05-25

Geotechnical Engineering Report 3 January 8,2021 Glint Car Wash and Sonic Everett,Everett,Washington RGI Project No.2020-643-1 More detailed descriptions of the subsurface conditions encountered are presented in the borings included in Appendix A. Sieve analyses were performed on four selected soil samples.The grain-size distribution curves are included in Appendix A. 4.4 GROUNDWATER Groundwater seepage was encountered at each boring location at depths of 2.5 to 10 feet during our subsurface exploration.The observed seepage appears to be indicative of perched groundwater collecting above the underlying dense soil deposits. It should be recognized that fluctuations of the groundwater table will occur due to seasonal variations in the amount of rainfall, runoff, and other factors not evident at the time the explorations were performed. In addition, perched water can develop within seams and layers contained in fill soils or higher permeability soils overlying less permeable soils following periods of heavy or prolonged precipitation. 4.5 SEISMIC CONSIDERATIONS Based on the International Building Code (IBC), RGI recommends the follow seismic parameters for design. Table 1 IBC Parameter j 2015 Value 2018 Value Site Soil Class'. D2 Site Latitude 47.904398 Site Longitude -122.24592 Short Period Spectral Response Acceleration,Ss(g) 1.445 1.39 1-Second Period Spectral Response Acceleration,Si(g) 0.56 0.494 Adjusted Short Period Spectral Response Acceleration,SMS(g) 1.445 1.39 Adjusted 1-Sec Period Spectral Response Acceleration,SM1(g) 0.84 0.8923 .._.......... ...................... ............ . ............. ................. ..................... ............................ .................. ....._........... .................................... . .................. .........._...... ................. ..:.............. . ................................................. Numeric seismic design value at 0.2 second;Sos(g) 0.963 0.926 Numeric seismic design value at 1.0 second;So1(g) 0.56 0.5953 1.Note:In general accordance with Chapter 20 of ASCE 7-10.The Site Class is based on the average characteristics of the upper 100 feet of the subsurface profile. 2. Note: The 2015 IBC and ASCE 7-16 require a site soil profile determination extending to a depth of 100 feet for seismic site classification.The current scope of our services does not include the required 100 foot soil profile determination.Test pit explorations extended to a maximum depth of 16 feet, and this seismic site class definition considers that similar soil continues below the maximum depth of the subsurface exploration. Additional exploration to deeper depths would be required to confirm the conditions below the current depth of exploration. 3.Note:In accordance with ASCE 11.4.8,a ground motion hazard analysis is not required for the following cases: Corporate Office 17522 Bothell Way Northeast Bothell,Washington 98011 Phone 425.415.0551• Fax 425.415.0311 www.riley-group.com