Laserfiche WebLink
0f�7 <br /> Golder Associates <br /> CONSULTING GEOTECHNICAL AND MINING ENGINEERS <br /> August 10 , 1984 Our Ref : 843-2044 <br /> RECEIVED <br /> Mid-Continent Resources , Inc. <br /> P.O. Box 158 AUG 101984 <br /> Carbondale , CO 81623 <br /> MINED LAND RECLAMATION DIVISION <br /> Attn : Mr, D. Bowman Environmental Coordinator Colo. Dept.of Natural Resources <br /> RE : Short-Term Stability , Proposed Sutey Waste Pile <br /> Coal Basin Mines , Redstone , Colorado <br /> Gentlemen: <br /> In their letter dated July 12 , 1984, the Mined Land Reclamation <br /> Division outlined their concerns regarding the stability of the <br /> proposed new Sutey waste pile. This letter and the attached <br /> calculations have been prepared in response to the questions <br /> raised by MLRD and hopefully satisfies their concerns. <br /> The overall critical geometry of the waste pile is outlined on <br /> Drawing No. 1028-013 , previously submitted. As shown on this <br /> drawing , the overall maximum height of the pile will be about 140 <br /> feet . Further , based on the information obtained at one borehole <br /> location , the waste pile will be underlain by about 47 feet of <br /> silty clay colluvial material overlying the Mancos Shale. <br /> The results of stability analyses carried out based on the <br /> proposed waste pile geometry for the long term (drained) case <br /> have been submitted previously. The results of these analyses <br /> indicate that the minimum factors of safety for the overall <br /> geometry proposed were 1.5 for the static case and 1 .3 when <br /> dynamic (earthquake) loading was considered. <br /> MLRD has expressed concern regarding the stability of the waste <br /> pile during the proposed construction schedule and Mid-Continent <br /> Resources has requested that Teo-Hydro (Golder Associates) review <br /> the stability of the pile during the proposed construction <br /> schedule. <br /> The evaluation of the short-term or intermediate term stability <br /> of the waste pile is a complex issue. When the waste materials <br /> are placed , excess pore pressures will develop in the colluvial <br /> silty clay soils underlying the waste pile. As these excess pore <br /> pressures dissipate , consolidation of the colluvial soils will <br /> GOLDER ASSOCIATES,INC •17301 W COLFAX AVENUE,SUITE 275.GOLDEN(DENVER),COLORADO 80401 U.S.A •TELEPHONE(303)278-8662 <br /> OFFICES IN CANADA•UNITED STATES•UNITED KINGDOM•AUSTRALIA <br />