17 E MARINE VIEW DR 2019 Geotech Report 2025-10-01

summary is presented for introductory purposes only and should be used in conjunction with the complete recommendations presented in this report. ■ The site is underlain by saturated loose sand that would be considered liquefiable under a design level earthquake. Earthquake induced soil liquefaction could result in 6 to 14 inches of settlement and many feet of lateral spreading.These conditions should be considered in the design of critical site structures. Is Consolidation settlement on the order of 3 to 6 inches will also result from the placement of the heavy loads associated with the soil and asphalt stockpiles.The stockpiles will induce up to 1/2-inch of settlement extending about 15 feet away from the edges of the 25-foot high stockpile locations. We recommend a 15-foot minimum setback from the toe of a stockpile to any settlement-sensitive structures or adjacent property. Site grades should also be established to accommodate this anticipated settlement, if needed. ■ The footprint if the planned soil remediation sheds and asphalt building should be preloaded and surcharged to induce as much primary consolidation settlement as possible before constructing the buildings.The preloads should be at least 25 feet high,and an additional 5-foot minimum surcharge (30 feet total)should be added to help accelerate the time rate of settlement.The surcharge should be left in place for at least 3 months or until settlement plates indicate that the desired settlement has been achieved. The existing recycled asphalt materials may be used as the preload and surcharge fill for each building footprint. Is Once the surcharge fill is removed, the lightly loaded shed structures can be supported on shallow foundations. We recommend an allowable soil bearing pressure of 2,500 pounds per square foot (psf)for foundations bearing on a minimum 2-foot thickness of properly compacted structural fill. ■ Imported structural fill consisting of sand and gravel should eb used below the building foundations. ■ The near-surface soils consist primarily of granular fill. Portions of the fill may be suitable for reuse as structural fill on the site,however,care should be taken to separate out any layers with high fines content or fill with unsuitable organic content or construction debris. Earthquake Engineering 2015 IBC Seismic Design Information For the Delta site soil remediation facility, we recommend the following 2015 International Building Code (IBC) parameters for the maximum-considered earthquake geometric mean (MCEG) and risk-targeted maximum-considered earthquake (MCER). The parameters presented below include: site class, peak horizontal acceleration (PGA), short period spectral response acceleration(Ss), 1-second period spectral response acceleration(Si), and Site Coefficients FPGA, FA and Fv presented in Table 1. TABLE 1.2015 IBC SEISMIC PARAMETERS 2015 IBC Parameter Recommended Values Site Class E MCEG,Peak Horizontal Acceleration PGA(percent g) 51.2 Site Coefficient,FPGA 1.188 Site Class Adjusted PGA„(percent g) 60.8 GEOENGINEER� August3,2018 Page6 file ho.0643-015 00