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Bozorgnia (2008), and Chiou and Youngs (2008). The results of the probabilistic seismrc hazard analysis indicate the modal seismic event is Moment Magnitude (Mw) 6.52. The SPT consists ofdriving a standard sampler, as described in the ASTM 1586 Standard Method, using a 140 pound hammer falling 30 inches. An Automatic Trip Hammer was used to drive samplers l8 inches into the soil. For the measured 76 percent hammer efficiency of an automatic hammer, the energy ratio 1.27 was used in our liquefaction evaluation. We have used the borehole diameter correction factor (CB) 1.0 in our liquefaction evaluation. For liquefaction of clayey soils, the screening criteria of Bray and Sancio (2006) were used to determine if fine-grained soils within boring B-l is susceptible to liquefaction. To determine if soils are susceptible to liquefaction. the Plasticity Index (PI) and in-situ moisture content were determined. For screening analysis purposes, all soil samples above and below the groundwater table were soaked and saturated, and then tested for moisture content. For PI greater than l2 and moisture content less than 85 percent of liquid limit. clayey soils are not susceptible to liquefaction. For sandy layers. we used methods proposed by Tokimatsu and Seed (1987) for liquefaction analysis. Based on our analysis and under the current site conditions. we estimate that the maximum total liquefaction-induced ground settlements at the site would of about L22 inches during the postulated earthquake. Differential settlements of approximately 0.81 inch or less could occur over a span of 40 feet. The computer outputs are included in Appendix C for reference. It is our opinion that potential for liquefaction at the site is low and will not adversely impact the proposed construction. 7.0 DESIGNRECOMMENDATIONS Based upon the results of our investigation. the proposed Accessory Dwelling Unit is considered geotechnically feasible provided the recommendations presented herein are incorporated into the design and construction. If changes in the design of the structure are made or variations or changed conditions are encountered during construction, GeoBoden should be contacted to evaluate their effects on these recommendations. The following geotechnical engineering recommendations for the Proposed Accessory Dwelling Unit are based on observations from the field investigation program and the physical test results. 7.1 EARTHWORK All earthworks. including excavation. backfill and preparation of subgrade, should be performed in accordance with the geotechnical recommendations presented in this report and 5 Dennis- l -0 1