Laserfiche WebLink
the geologic record and historical records of tsunamis in Japan, it is believed that the most recent CSZ <br />event occurred in 1700. <br />5.2.2.2018 IBC Seismic Design Information <br />For the site, we recommend the IBC 2018 parameters for Site Class C, mapped risk -targeted maximum <br />considered earthquake (MCER) spectral response acceleration at short period (Ss), mapped MCER spectral <br />response acceleration at 1-second period (Si), short period site coefficient (Fa), long period site coefficient <br />(Fv), design spectral acceleration at 0.2-second period (SDs) and the design spectral acceleration at <br />1.0-second period (SDI). The following table shows the recommended values for these parameters. <br />TABLE 1. 2018 IBC DESIGN PARAMETERS <br />2018 IBC Parameter' <br />Recommended Value <br />Site Class <br />C <br />Short Period Spectral Response Acceleration, Ss (percent g) <br />138.7 <br />1-Second Period Spectral Response Acceleration, S, (percent g) <br />49.3 <br />Seismic Coefficient, Fa <br />1.2 <br />Seismic Coefficient, Fv <br />1.5 <br />Short Period Design Spectral Response Acceleration, SDs (percent g) <br />111-0 <br />1-Second Period Design Spectral Response Acceleration, SD1 (percent g) <br />49.3 <br />Note: <br />'Parameters developed based on latitude 47.923435 and longitude-122.271847 using the Applied Technology Council (ATC) <br />Hazards online tool(https://hazards_atcouncil.org/). <br />5.2.3. Liquefaction <br />Liquefaction refers to the condition by which vibration or shaking of the ground, usually from earthquake <br />forces, results in the development of excess pore pressures in saturated soils with subsequent loss of <br />strength- In general, soils that are susceptible to liquefaction include very loose to medium dense, clean to <br />silty sands that are below the water table - <br />Ground settlement, lateral spreading and/or sand boils may result from soil liquefaction. Structures <br />supported on liquefied soils could suffer foundation settlement or lateral movement that could be severely <br />damaging to structures. Based on the subsurface soil and groundwater conditions encountered in the <br />explorations completed at the site, it is our opinion that the site has a low risk of liquefaction for a moderate <br />to large design earthquake. <br />5.2.4.Other Seismic Hazards <br />Due to the location of the site and the site's topography, the risk of adverse impacts resulting from <br />seismically -induced slope instability, differential settlement, surface displacement due to faulting, or lateral <br />spreading is considered to be low. <br />5.3. Subgrade Reaction Springs <br />We understand that foundation improvements for the proposed HBL positions are required to meet strict <br />deflection tolerances within each position for precise operation of robots and machines that are tracking <br />GEOENGINEER June 15, 2022 Page 5 <br />File No. 4120-294-02, <br />