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color. Samples of the natural sands classified as SM soils in accordance with the Unified Soil Classification <br />System. <br />Weathered claystone was encountered in all of the test holes beneath the sands or fill materials and <br />extended to depths ranging from 15 to 21 1/2 feet bgs. The weathered claystone materials were nil to slightly <br />sandy, moderately to highly plastic, blocky, moist to very moist and brown to gray in color. Samples of the <br />weathered claystone bedrock materials classified as CL to CH soils in accordance with the Unified Soil <br />Classification System. <br />Claystone bedrock was encountered beneath the weathered claystone in all of the test holes, and extended <br />to the maximum depth investigated in each of the test holes. Practical rig refusal was encountered at depths <br />ranging from 23 to 28 feet bgs in Test Holes 1, 4, and 6 in very hard bedrock materials. The claystone <br />bedrock materials were nil to slightly sandy, moderately to highly plastic, hard to very hard, slightly moist <br />to moist and brown to gray in color. Samples of the claystone bedrock classified as CL soils in accordance <br />with the Unified Soil Classification System. <br />An unconfined- compressive strength test conducted on a sample of the fill materials yielded an unconfined - <br />compressive strength value 1,300 psf. Unconfined- compressive strength testing of the weathered claystone <br />materials yielded unconfined - compressive strength values ranging from 3,700 to 9,700 psf Unconfined- <br />compressive strength testing of the claystone bedrock yielded unconfined- compressive strength values <br />ranging from 12,200 to 16,000 psf. The unconfined - compressive strength test results are presented in <br />Table I with all of the other laboratory test results. <br />Groundwater seepage was encountered in Test Holes 4 and 5 at the time of drilling at depths of 13 and 16 <br />'A feet bgs, respectively. However, when measured 3 days after the drilling was completed, groundwater <br />was also encountered in Test Holes 3 and 6. The depth of groundwater in the test holes ranged from 12 to <br />19 feet bgs. Groundwater measurements were also taken 38 and 124 days after the drilling was completed. <br />Groundwater was measured in Test Holes 3 through 6 at depths ranging from 12 to 17 feet bgs. <br />Groundwater was not encountered in Test Hole 2; however, the hole had caved at a depth of 17 feet bgs <br />when measured 38 days after the drilling was completed. Groundwater conditions should be expected to <br />fluctuate significantly with changes in precipitation and runoff at the site. <br />Slope Failure Analysis <br />Based on the results of the field and laboratory investigations, and our discussion with the client regarding <br />the previous work/regrading completed at the site, NWCC believes the slope failure can be characterized as <br />a small to moderate sized slump displaying rotational and translational movement. The failure surface <br />appears to be located within the deeper fill materials, natural sands and weathered claystone materials just <br />above the competent bedrock surface. <br />Job Number 11 -8970 <br />:`: ,11CC I P age 1 <br />�s <br />