Laserfiche WebLink
-4- <br />~~ <br />U <br />location of The borings, establish sampling intervals and log the materials found in <br />each boring. Graphical representations of the materials found in each boring are <br />presented in Appendix A. <br />We sampled available rock materials for underdrains. Sandstone samples <br />were obtained from four surface outcrop locations near the spoil disposal site <br />(Sheet I, Fig. I). Representative overburden materials were sampled at three <br />levels within the existing pit. <br />Samples of the materials obtained from the borings and bulk sompling were <br />returned to our laboratory for further analysis and testing. Laboratory analyses <br />conducted as part of this investigation included classification tests, consolidation <br />tests, unconfined compressive and triaxial shear strength tests on natural soils and <br />bedrock; and point-load tests, specific gravity, slake-durability and pH tests on <br />(~ potential underdrain materials. <br />PREVIOUS STUDIES <br />CTL/Thompson, Inc. has performed several previous investigations at this <br />site, including stability analysis of the Streeter Canyon Fill. The Colowyo Coal <br />Company has also had several other consultants prepare geotechnical <br />investigations and we reviewed the information contained in these reports during <br />our site visit. The previous data was useful in establishing representative <br />parameters for stability analyses and furthered our understanding of the nature of <br />materials typically deposited in excess spoil areas at this site, the methods used to <br />place the fill and the characteristics of this spoil. <br />Our firm has performed geotechnical services at nearby mines within Moffat <br />County and Routt County where similiar materials are found and similiar mining <br /> <br />