1901-1919 N Fairview St - Soils Report

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603284-001 3.2.2 Seismically-Induced Settlement Seismically-induced settlement consists of dry dynamic settlement (above groundwater) and liquefaction-induced settlement (below groundwater). These settlements occur primarily within loose to medium dense sandy soil due to reduction in volume during, and shortly after, an earthquake event. Our analysis is presented in Appendix E. The seismically-induced settlement resulting from the design event is estimated to be in the order of 1 to 2 inches. Differential settlement is estimated to be approximately 7 inch over 100 feet. 3.2.3 Surface Manifestation of Liquefaction Surface manifestation of liquefaction would include the formation of sand/gravel boils and ground cracking. As discussed above, the site is generally classified as having low risk of liquefaction based on LPI. Accordingly, the potential for surface manifestations, such as sand boils or bearing capacity failure of shallow foundations, is considered low. 3.2.4 Lateral Spreading or Flow Failure For lateral spreading or flow failure to occur, a continuous, laterally unconstrained liquefiable zone must be free to move along gently sloping ground toward an unconfined area. The site is relatively flat. Although the Santa Ana river channel and levee are located approximately 200 feet south and east of the site, the river channel depth is generally shallower than the soil layers at the site deemed susceptible to liquefaction. Accordingly, the potential for lateral spreading is deemed low. 3.2.5 Seismically-Induced Landslides According to the State of California Seismic Hazards Zones Map for the Anaheim Quadrangle, the site is not located in an area potentially susceptible to earthquake induced landslides. Based our experience and the gently sloping topographic character of the site, the potential for seismically-induced slope instability is considered low. -14- Leighton