Laserfiche WebLink
•~ Based on the granular nature of the material in the pile today, it II <br />appears that there is no plasticity. The strength is therefore I <br />expected to be a result of frictional resistance. Tests of similar ~ <br />material in direct and triaxial shear performed by Chen and <br />Associates (Soil and Geological investigation for Proposed <br />Overburden Waste Piles and Sedimentat' m King Mines, New <br />Castle, Colorado, dated Mar , 1982, Table A, p. 1 uced an <br />effective stress frict' angle of 28~°, with no cohesion. This <br />value seems consistent w ld be <br />expected in a granular material. <br />With respect to chemical composition, the waste roc}; material is <br />almost always described as calcareous, and there is only occasional <br />identification of disseminated pyrite. The rock materials have <br />been tested for chemical composition, and the results reported ir. <br />Appendix 3.3-1. The results of this testing are summarized in <br />Table 1. This information indicates that the rock materials are <br />not combustible. Further, the waste rock does not appear to have <br />the potential to produce acid leachate: pyrite levels are <br />considerably too low, and there appears to be a large <br />neutralization potential, both from its description as generally <br />"calcareous", and from the high leach Ph values. The last material <br />is coal: note the high combustible solids, and the low pyrite <br />content. <br /> <br />Table 1 - significant chemical characteristics <br />•.i <br />of waste rocY. <br />HOLE SAMPLE TOTAL PYRITE LEACH <br /> DEPTH COMBUST CONTENT WATER <br /> (feet) SOLIDS pH <br />SK-3.75 ?(~1) 14$ 0.34$ 8.1 <br />SK-3.75 ?(~2) 13$ 0.29$ 8.0 <br />SR-3.75 ?(#3) 10$ 0.09$ 8.5 <br />SK-8A 998 14$ 0.30$ 7.1 <br />SR-SA 1041 15$ 0.40$ 7.7 <br />SK-SA 1077 13$ 0.10$ 7.6 <br />SK-7 (coal) 1448 91$ 0.03$ NA <br />:;.2 Foundation Material <br />The foundation material in the vicinity of the pads is made up of <br />colluvial material resulting from mass wasting of the hogbacY, <br />above. Two typical geological sections through the prciect area <br />are presented on Figure 5.2-2 and 5.2-3 in the main repcrt. <br />The grainsize of the materials was also sampled, and is presented <br />as Pit l..in Figure 1. The foundation material grainsize ranges <br />from silt to house size, and is very heterogeneous. However the <br />. dominant size range for these materials is in the sand range, with <br />Adrian Brown Consultant: -5- 1145/4005:1 <br />