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EARTH DYNAMICS LLC ReMi Analysis 1200 Alder St October, 2025 Page 5 5.0 DISCUSSION 5.1 Site Geology Draft logs from exploratory borings completed at this site indicate that the subsurface geology consists of sandy silts, clays and clayey silt to a depth of approximately 80 feet bgs. The deepest boring log was advanced to a dept of 80 feet bgs. Therefore, there is no boring log data available below that depth. The modelled ReMi data appears to correspond well with the data in the boring logs. 5.2 ASCE Classifications ASCE 7-22 (2022) defines eight site classes based upon the average shear-wave velocity of the soil to a depth of 30 Meters (100 feet). The ASCE classification is summarized in Table 5-1. Earthquake shaking is expected to be stronger where shear-wave velocity is lower. Average shear wave velocity to a depth of 100 ft (Vs100) is calculated using Equation 5-1. 𝑉𝑠ሺ100ሻ ൌ ଵ଴଴ ∑൬ ೏೔ ೇೞ೔൰೔స೙೔సభ Equation 5-1 Where: n = the number of intervals i = the interval number di = the thickness of the ith interval in feet Vsi = the velocity of the ith interval Using Equation 5-1 and the data in Figure 4-2, the average shear wave velocity to a depth of 100 ft is calculated to be 974 ft/s for this ReMi Array. The modelled velocity is in the for ASCE 7-22 seismic design site classification of “D”. Table 5-1. Summary of ASCE 7-22 soil classification. Class Average S-wave Velocity (ft/sec) Description A > 5,000 Hard rock B >3,000 –5,000 Medium hard rock BC >2,100 –3,000 Soft rock C >1,450 –2,100 Very dense sand or very stiff clay CD >1,000 –1,450 Dense sand or very stiff clay D >700 – 1,000 Medium dense sand or stiff clay DE >500 –700 Loose sand or medium stiff clay E ≥500 Very loose sand or soft clay