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Rock Strength and Physical Pape fres— HC001-14, HC002-155 MC00345, <br />HC00/-15, HC005-14 HC008-15, and HC007-15 <br />Paye 3 <br />3.2.1 Uniaxial Compressive Strength Test <br />The uniaxial compressive specimens were loaded at a constant rate, chosen so <br />that fame would occur within the two (2) minute to fifteen (15) minute period set forth in <br />the ASTM (ASTM D 7012-04, Method C) specifications_ The loading rate for all uniaxial <br />compressive strength specimens was programmed into the computer as a ramp <br />function defined as 9,000 Ib/min. <br />After placing the specimen between a set of hardened steel platens, the machine <br />was then accelerated to the pre -selected loading rate. The data acquisition unit contin- <br />uously monitored the load, cumulative test time, and position of the lower platen. The <br />uniaxial compressive strength is calculated as the load at failure divided by the <br />specimen area as indicated by equation 1 below. <br />ac= <br />ReD`)14] <br />Eq. 1 <br />Where: <br />ac = compressive strength (Ibiin2), <br />P = peak or failure load (lb), <br />D = specimen diameter (inches), and <br />R = constant, 3.1416. <br />3.22 Bulk Density and Specific Gravity <br />The bulk density of the uniaxial compressive strength specimens was determined <br />by weighing the specimens to the nearest 0.1 gm, converting grams to pounds, and <br />dividing the weight in pounds by the sample volume determined from measurements of <br />diameter and height. The dimensions of the specimen were used since the rock is <br />machined to a perfect right cylinder for the uniaudal compressive strength tests. The <br />conversion between bulk density and specific gravity involves dividing the bulk density <br />by 62.4 Ibift3, the unit weight of water. <br />IV. Test Results for All Boreholes <br />The results for the uniaxial compressive strength tests can be found in Exhibit A. <br />The specimen location photographs can be found in Exhibit B and the photographs of <br />the core can be found in Exhibit C. <br />