4102 RUCKER AVE SAFEWAY FUELING STATION 2016-01-01 MF Import

GEOTECHNICAL ENGINEERING STUDY Inform,lnc May 9, 2002 E-8493-5 Page 9 Liquehction: Liquefaction is a phenomenon in which soils Iose all shear strength for short periods of time during an earthquake. Groundshaking of sufficient duration results in the �oss of grain to grain contact and rapid increase in pore water pressure, causing the soil to behave as a fluid. To have a potential for liquefaction, a soil must be cohesionless with a grain size distribution of a specified range (generally sand and siltl; it must be loose; it must be below the groundwater table; and it must be subject to sufficient magnitude and duration of groundshaking. The effects of liquefaction may be large total and/or differential settlement for structures founded in the liquefying soils. Based on the soil and groundwater conditions encountered at the site, it is our opinion the site has a low susceptibility to liquefaction. Ground Motan Response: The 1997 UBC Earthquake regulations contain a static force procedure for design base shear calculations. Based on the encountered soil conditions it is our opinion soil profile type S�, Very Dense Soil or Soft Rock, as defined in Table 16-J, should be used to characterize the site soils. Excavations and Slopes The following information is provided solely as a service to our client. Under no circumstances should this information be interpreted to mean that ECI is assuming responsibility for construction site safety or the contractor's activities; such responsibility is not being implied and should not be inferred. The inclination of temporary slopes is dependent on several variables, including the height of the cut, the soil type and density, the presence of groundwater seepage, construction timing, weather, and surcharge loads from adjacent structures, roads and equipment. In no case should excavation slopes be greater than the limits specified in local, state (WISHAI, and Federal 10SHA) safety regulations. In our opinion, the medium dense fill and native soil encountered at our boring locations would be classified as Type C based on Washington Administrative Code (WAC) 296, Part N. Earth Consultants,lnc.