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<br />' production from County Road 44 to Mr. Roushar's property is south <br />of any proposed production, therefore, will not be affected. <br />Stability <br />The angle of repose is the angle from a horizontal plane that a <br />dry, loose cohesionless granular soil is stable. For the <br />' existing granular material the angle of repose is on the order of <br />32 to 36 degrees. The angle of repose can be considered equal to <br />t the angle of internal friction when the soils are in a very loose <br />condition. However, the angle of internal friction increases <br />' with increased density and is dependent on particle size, shape, <br />gradation and composition. The existing pit run material is <br />medium dense to dense. Thus, an internal friction angle on the <br />order of 40 to 44 degrees in reasonable for the pit run material. <br />For a purely cohesionless material the slope stability equation <br />' reduces to: <br />' tangy <br />S. F. _ <br />tanr= <br />Where ~ = internal friction angle <br />' it = angle of repose <br />' Usinq the above formula for the pit run material at a slope angle <br />equal to the angle of repose produces a safety factor ranging <br />' from 1.15 to 1.54 with the range of friction angles presented. <br />The small layers of clay present in the mined pit run material <br />' add some cohesion to the deposit. This fact was not factored <br />into the slope stability analysis; however the effect would <br />increase the cohesion, thus increase the safety factor. <br />It planned to mine and reclaim the pit with 3:1 side slopes. <br />cohesionless soil slopes do not fail in rotational type failures <br />but in slough or wedge type failure where the angle of the cut <br />11 <br />