Laserfiche WebLink
GEOTECHNICAL STABILITY EXHIBIT <br />There are no buildings or any structures outside the permit azea which could be affected by the <br />operation. All reclaimed areas will be restored to relatively flat (<5%) slopes except for the cut <br />slopes to the north, which will be reclaimed to a 2.OH:1.OV slope. The existing pit has been in <br />place since 1977 and has been permitted to leave 2H:1 V slopes on the north side of the pit. Over <br />the past 25 years, there has never been a problem with slope stability of these cuts. In fact, many of <br />the past pit excavations aze much steeper than 2H:1 V and have never had any stability problems. <br />The gravel zone has a good mix of fines and gravel sizes and has been fairly well compacted and <br />cemented over time. The operator has committed to mine the slopes no steeper than 2H:1 V, <br />therefore, the original ground will make up the final slope; not imported material to attain the <br />slope. <br />The natural gavel material has some cohesion and has well-cemented fines. This results in slope <br />stability parameters of cohesion and internal angle of friction of high values. When this is <br />combined with a relatively mild slope of 2H:1 V, it is expected that the safety factor for this short <br />slope will be above 1.5. I, Greg Lewicki, P.E., with over 20 yeazs of experience in mine slope <br />safety analysis in Colorado, state that this is true. <br />North R-34 Pit 1/07 <br />52 <br />