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1100318 R0T0 0811 JRW1 1 <br />1 Introduction <br />At the request of counsel for Continental Materials Corporation,1 Ungaretti & Harris, Exponent <br />Failure Analysis Associates (Exponent) conducted an investigation of the December 2, 2008 <br />landslide at the Pikeview Quarry located in Section 9, Township 13 South, Range 67 West, 6th <br />Principal Meridian in El Paso County, Colorado. Based on Exponent’s investigation, we have <br />concluded the following: <br /> The Pikeview Quarry is not just land. It is an engineered improvement <br />designed to allow the quarry owner to remove, for commercial purposes, raw <br />materials consisting of saleable aggregates, particularly limestone. For <br />illustration, the quarry is a designed excavation that embodies engineering <br />considerations similar to those utilized in highway embankments and in <br />excavations for high rise buildings and is a substantially more engineered <br />structure than a typical residential structure. <br /> The December 2, 2008 landslide damaged the engineered improvements of <br />the Pikeview Quarry to the extent that the quarry owner could not recover <br />saleable aggregates, particularly limestone. <br /> The December 2, 2008 landslide was caused by a heretofore unknown, weak, <br />laterally extensive clay bed in the upper portion of the Sawatch Formation <br />that extends from the top of the quarry to beneath Area H. The presence of <br />the clay bed in the upper portion of the Sawatch Formation is the single most <br />significant destabilizing condition present in the Pikeview Quarry slope. In <br />the absence of this clay bed, the west slope would have been stable with a <br />factor of safety in excess of 4.2 The significance of this result is that the <br />December 2, 2008 landslide would not have occurred without the presence of <br />the clay bed. <br /> <br />1 Owner of Pikeview Quarry <br />2 A slope stability analysis Factor of Safety is a measure of stability of a slope. Factors of Safety less than <br />one (1.0) indicate an unstable slope, i.e., one that will fail. Standard Factor of Safety for slopes used by <br />reviewing agencies and municipalities for static conditions varies between 1.3 and 1.5. A Factor of Safety of 4 <br />far exceeds minimum acceptable Factors of Safety.