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Page 5 <br /> <br />Note: In accordance with the California Geological Survey (CGS), Special Publication <br />(SP) 117A, one of the methods to mitigate the potential adverse effects due to potential <br />liquefaction is using a strengthened foundation system; therefore, a strengthened <br />foundation system is recommended to be used for support of the purposed structures (see <br />“Building Foundation Design Guidelines” section of this report). <br /> <br />Potential Consequences of Liquefaction or Secondary Liquefaction Included Hazards <br /> <br />Potential consequences of liquefaction or secondary liquefaction included hazards <br />generally consist of differential settlement (vertical deformations), lateral <br />movement/lateral spreading (horizontal deformations), oscillation, and reduction in <br />foundation soil-bearing capacity (bearing failure). <br /> <br />A sloping condition or drainage or stream channel does not exist at the site; therefore, <br />lateral movement/lateral spreading, oscillation, etc. due to potential liquefaction are not <br />anticipated to be credible hazards for the proposed new structure. <br /> <br />We believe if the area would be “liquefied” in the future due to a very strong earthquake, <br />the potential damage to the proposed new structures which will be properly structurally <br />designed in accordance with the new up-to-date codes would be much less severe than <br />the existing on-site structures and surrounding existing houses which have been <br />previously structurally designed based on old codes (which are much less stringent than <br />the current new codes). However, the owner(s) of this property should be aware of the <br />potential damage to the new structures due to liquefaction. <br /> <br />In summary, it should be recognized that structural mitigation may not reduce the <br />potential of the soils to liquefy during an earthquake; and there will remain some risk that <br />the new structures could still suffer damage if liquefaction occurs, during a very strong <br />earthquake. <br /> <br />For conservative purposes, a strengthened / stiffened foundation system as <br />recommended in this report should be used for support of the proposed structure. <br /> <br />Slope Stability <br /> <br />The site is a flat area; therefore, slope instability is not a concern for the proposed <br />development. <br /> <br />CONCLUSIONS AND RECOMMENDATIONS <br /> <br />General Conclusions <br /> <br />Construction of the proposed structure at the subject site is considered geotechnically <br />feasible, provided the recommendations outlined in this report are implemented. <br />