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1100318 R0T0 0811 JRW1 32 <br />bedrock. Although there is no record as to the type of drilling utilized, quarry <br />personnel indicate that they were not aware of any prior rock coring being <br />undertaken at the quarry. Based on this information and the relative lack of <br />detail of these logs, it appears that they were either advanced using air rotary <br />or air percussion drilling methods. Identification of the previously unknown <br />clay bed observed during Exponent’s borings would have been virtually <br />impossible unless the type of borings performed as part of this investigation <br />(i.e. rock core borings) were performed. The standard drilling techniques <br />previously utilized at the site would not have facilitated identification of these <br />clay beds. <br />5.2.4 Laboratory Testing <br />Laboratory testing was performed to characterize the engineering properties of the clay bed, the <br />various members of the Manitou and Sawatch Formations, and the Pikes Peak Granite. The <br />results of laboratory testing are contained in Appendix 43. <br />The consistency and chemical composition of the clay bed were tested. Samples from the clay <br />bed encountered in trench TR-1 (Area H) were tested for moisture content, Atterberg limits, <br />particle size distribution, and specific gravity. Samples of clay from cores EXC-1, EXC-2, and <br />EXC-4 and trench TR-1 were tested by x-ray diffraction (XRD) to determine their chemical <br />composition. The engineering properties determined from this testing indicates that the clay <br />beds observed in the cores and trench are essentially the same material. It is therefore <br />concluded that the encountered clay beds are continuous between the sampled locations in Area <br />H to the locations at the top of the quarry. This conclusion is consistent with the depositional <br />history of the marine environment in which these beds were formed. <br />Samples from the clay bed encountered in cores EXC-1, EXC-2, and EXC-4 and trench TR-1 <br />were tested for their strength properties. Intact and remolded clay specimens were prepared for <br />direct shear testing. The intact specimens were produced from clay samples collected during <br />rock coring. These samples were repeatedly cut/trimmed and carefully inserted into a standard <br />2.4 inch diameter, 1 inch high stainless steel ring until the properly sized specimen was