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I <br /> Interwest Construction Co.-Everett Contractor Yard Site Improvements,Everett,WA March 12,2021 <br /> IGeotechnical Engineering Report P2184-T20 <br /> Class E. Our evaluation assumes the soil conditions encountered in the bottom of our explorations, <br /> I and those from nearby properties,is similar to or increasing in density/consistency down to 100 feet <br /> below ground surface. <br /> I The 2015 IBC considers earthquake shaking having a 2 percent probability of exceedance in 50 years <br /> (i.e. a 2475-year return period), as the code-based design requirement. Using the third-party <br /> graphical user interface tools made available by the USGS at https://seismicmaps.org,MGI derived <br /> the design ground motions to be used for design of the structures. Our evaluation used ASCE 7-16 <br /> as the code reference, Risk Category I/II/III, and Site Class E. The results of our evaluation are <br /> provided in Table 3 (below). <br /> TABLE 2 <br /> SEISMIC DESIGN PARAMETERS <br /> Parameter Value Basis <br /> Site Class E Site specific data <br /> Ss 1.214 seismicmaps.org <br /> I <br /> Fa 1.2^ seismicmaps.org <br /> SMS 1.457 =Fa Ss <br /> SOS 0.971 =2/3 SMS <br /> SI 0.431 seismicmaps.org <br /> Fv 1.7 B-C 2015 IBC <br /> SMI 0.733 B-C =Fv So <br /> SDI 0.488B'C =2/3 SMI <br /> PGA 0.520g seismicmaps.org <br /> I <br /> PGAM 0.614g seismicmaps.org <br /> ITo --C Not applicable <br /> Not applicable <br /> TL 6 sec. seismicmaps.org <br /> Notes: <br /> A.I Use the value provided unlessI the simplified design procedure of ASCE 7 Section 12.14 is <br /> used. If this occurs,please contact our office for more information. <br /> B. Based on Table 1613.2.3(2)of the 2015 IBC-An ASCE 7-16 Chapter 21 analysis has not been <br /> performed. <br /> C. More detailed seismic design criteria are available upon request. Please contact MGI's office <br /> Ifor more information. <br /> 3.5 Liquefaction Potential <br /> ILiquefaction is a sudden increase in pore water pressure and a sudden loss of soil shear strength <br /> caused by shear strains, as could result from an earthquake. Research has shown that saturated, <br /> I loose,fine to medium sands with a fines(silt and clay)content less than about 20 percent are most <br /> susceptible to liquefaction. <br /> Given the presence of extensive saturated, poorly consolidated soils underlying the proposed <br /> improvement area,we interpret the upper site soils as having a moderate potential for liquefaction <br /> I Migizi Group, Inc. Page 5 of 16 <br /> MIGILI Illilil ,.,, II <br />