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Direct Shear <br />We performed three direct shear tests on samples which were extruded from Shelby tubes. <br />The direct shear test is used to determine the friction angle and cohesion intercept for soils; both <br />values are used in analyzing stability. We obtained reasonably consistent results for each test. Tests <br />were run at natural moisture and on flooded samples. We tested one sample from the very wet layer <br />(Boring 10.3 at 4 feet). This sample exhibited a friction angle value of 35 degrees and a cohesion <br />intercept of 800 pounds per square foot. A sample from the deeper dryer materials (Boring 106 at <br />24 feet) exhibted a friction angle value of 30 degrees and a cohesion intercept of 600 pounds per <br />square foot. The third sample was flooded to determine if saturating the sample would have an affect <br />on the shear strength. A sample from Boring 106 at 19 feet was used and exhibited a tiction angle <br />of 31 degrees and a cohesion intercept of 500 pounds per square foot. <br />DENSfTY TESTING RESULTS <br />The information obtained in the field was compiled as shown on Table C-1. We compared the <br />laboratory moisture contents for each depth. We found a reasonably consistent ratio between the <br />nuclear (Troxler) moistures and the fab moistures of 4.6. We used this value as our moisture correction <br />factor. We also observed a reasonably consistent ratio between the down-hole nuclear dry densities <br />and the Troxier dry densities of 1.1. We used this value as a density correction factor. We corrected <br />the densities from our earlier study using these correction factors. These are shown on Tables C-2 <br />through C-7. The maximum dry density was calculated using an average of the three standard <br />Proctors. This average density was used to estimate percent compaction. The estimated "average" <br />density for the six holes drilled previously ranged from about 80 to 100 percent. <br />6 <br />