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Slope Evaluation and Remediation <br />West Elk Mine <br />Somerset, Colorado <br />installation of numerous structural elements (micropiles) to remediate landslide <br />movement. It is GROUND's interpretation that the smaller landslide feature currently <br />under evaluation by this scope of service is moving distinctly faster and separate from <br />the underlying older landslide complex studied by others. <br />SUBSURFACE CONDITIONS <br />The subsurface conditions encountered in Test Holes 1 through 5, generally consisted of <br />fill materials derived from local sources or native sands and clays. Due to their similarity, <br />it was difficult to distinguish between fill and native materials that are both part of the <br />more recent landslide feature. Regardless, these materials were underlain by an older <br />landslide complex that extended to the test hole termination depths of 30 to 40 feet <br />below existing grades. Practical drill rig refusal conditions were encountered in Test <br />Holes 1 and 2, presumably due to large resistant sandstone bedrock or boulders. The <br />bedrock encountered on -site is interpreted to be part of the Cretaceous -aged Mesaverde <br />Formation. <br />Landslide (recent) materials that are associated with the smaller and rapidly moving <br />feature include: <br />• Fill generally consisted of sandy clays to clayey sands with pieces of sandstone <br />and claystone / shale bedrock as well as gravel, cobbles and boulders. They <br />were generally fine to coarse grained with gravels, cobbles, and boulders, low to <br />medium plastic, loose to very dense, dry to moist, and brown to dark brown in <br />color. <br />• Native Sands and Clays were generally clayey sands to sandy clays, and <br />contained layers and lenses of gravels. They were generally fine to coarse <br />grained with some gravels, low plastic, medium dense to very dense, dry to <br />moist, and brown to black in color. <br />Landslide (older) materials that are associated with the larger and slowly moving <br />complex include: <br />• Landslide materials consisted of disarticulated claystone / shale bedrock bound <br />by competent and massively bedded sandstone bedrock that is interpreted to <br />represent the older landslide complex. These materials were fine to coarse <br />grained, gray to dark brown or yellow to tan to red in color, medium to very hard, <br />Job No. 11 -6014 GROUND Engineering Consultants, Inc. Page 5 <br />