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on the order of 35 to 38 degrees. Unit weights varied from 92 to 120 pcf. <br />The properties for the spoil used in the stability analysis were: <br />Friction Angle ~ -Normal Value 35 degrees, Lower Bound 30 degrees <br />Unit Weight - 100 pcf <br />~ Cohesion C - 0 psf <br />Bedrock. The claystone bedrock was hard to very hard. An <br /> <br />unconfined compressive test indicated a strength of 16,220 psf. Due to the <br />high penetration resistance drive samples were typically less than 3 inches <br />in length. CTL/Thompson, Inc. has performed several previous investigations <br />~ near this site (References 3 and 4). Previous triaxial testing of intact bedrock <br />samples indicated compressive strengths greater than 100,000 psf at in-situ <br />confining pressures. Based upon our experience and the results of the field <br />~ • exploration a strength value of 25 degrees friction and 5,000 psf cohesion <br />was used for bedrock. <br />Water Conditions. Water was noted during excavation of TP-3B <br />directly above the bedrock at a depth of 11 feet. In boring TH-3 water was <br />first encountered near the bedrock layer and quickly rose to a depth of 1 foot. <br />~ One day after drilling water was at a depth of 0.5 feet (Elev. 6850) in boring <br />TH-3. Water was found perched in a gravel layer above the bedrock in boring <br />TH-5 at depths of 23 feet during drilling and one day after drilling. The <br />~ remaining borings in the area of the revised RDA were dry. <br />The water found in boring TH-3 was at an elevation very close to the <br />• <br />water surface elevation in Sedimentation Pond D at the time of drilling. The <br />. lowest and closest portion of the proposed RDA is located about 150 feet <br />13 <br /> <br />