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1 1 The proctor and direct shear tests were performed on the material ' passing the number 4 sieve. The results are interesting and accurately reflect the material in the pile and the "downspoiling" manner in which the pile was constructed. The ' results show that the material has a Unified Classification as a SW-SM soil which is a silty sand. The direct shear tests were performed at the actual density of the placed material or 116 lbs/cu.ft -dry. The tests showed a cohesion of zero and an ' internal angle of friction of 37 degrees. This means that the material cannot resist applied lateral forces because there is not enough binding clay present, yet, the jagged nature of the ' material (from blasting) has resulted in a very high angle of friction. ' Since the angle of 37 degrees was determined for the material passing the number 4 sieve and this material represented only 46 $ of the total sample, an adjustment must be made for the total material. All material not passing through this sieve is greater ' than 1/4 inch in diameter. This material will also have no cohesion, however, its internal friction angle should be even greater, up to 44 degrees. See the enclosed table from "Stability ' Analysis of Earth Slopes" by DR. Yang Huang describing the average effective shear strength of compacted soils. ' Therefore, the internal angle of friction of the overall material is more accurately stated as 41 degrees. ' 3. Slone Stability Analyses ' The REAME computer model for slope stability analysis developed by Yang Huang of the University of Kentucky is used in determining the slope safety factor of the rock fill. This program is based on the Bishop's method of slices for cylindrical failure. ' The material properties used as input for the program are as follows: ' Dry Density 116 lbs/cu.ft Cohesion 0 lbs/sq.ft. ' Angle of Friction 41 degrees u I 1