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Project No. JB-20100 4 December 2000 Page 3 A resistance value (R-Value) test was performed on a representative bulk sample of the probable pavement subgrade soils. The R-Value test was performed according to California Department of Transportation (Caltrans) test methods. The test result was an R-Value of 18. 3.0 SUBSURFACE CONDITIONS 3.1 Surface At the time of our field exploration, the subject site was observed to be an open lot as shown in Figures 9 and 10, Photographs of Project Site. The subject property is approximately 225 feet wide and175 feet long. The site is currently an open lot covered with seasonal grasses. The site is relatively flat and appears to drain to the streets. Some ponding may occur on the site. 3.2 Subsurface • Fill was not encountered in the borings at the time of our field exploration. There may be fill in areas beyond or between our exploratory borings. In general, the native soils consisted of loose to medium dense sandy silt overlying very dense gravelly sand at a depth of about 24 feet. Observations indicate that the near surface soils have a low expansion potential. Groundwater was not encountered at the time of backfilling the borings. We expect groundwater levels to fluctuate due to variations in rainfall, groundwater recharge, and site conditions. 3.3 Seismic and Liquefaction Considerations Geologic references indicate that no fault trace designated active or potentially active passes through the subject property. The nearest active fault (Jennings, 1994) is the Greenville Fault. The Greenville Fault is approximately 12 miles from the site. The maximum moment magnitude for the Greenville Fault (CDMG Open-File Report 96-08, 1996) is 6.9. The subject site is located in Zone 4 as defined by the Uniform Building Code (1997 edition) on Figure 16-3, Seismic Zone Map of the United States. Based on the soils encountered in the borings the most appropriate Soil Profile ! Type would be SE. 1 It is our opinion, based on the soil conditions encountered in the borings, that the site soils encountered have a low potential of soil liquefaction. �Ko rbmachar Engineering, Inc.