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The stereonet information was used to organize the discontinuities into five (5) sets. These <br /> sets were shown previously in Figure 2-1 and are described below(orientations follow the <br /> dip/dip direction convention): <br /> • F1: A sub-horizonal joint set that is typically undulating and planar with localized <br /> steeply dipping areas. The average plane for the South Quarry is 8, 65, and the <br /> average plane for the West Quarry is 11, 223. <br /> • J1: A steeply dipping joint set that trends north-south. The average plane for this <br /> joint set is 83, 275 in the South Quarry and 90, 270 in the West Quarry. <br /> • J2: A steeply dipping joint set that trends east-west. The average plane for this joint <br /> set is 86, 336 in the South Quarry and 85, 183 in the West Quarry. <br /> • J3: A steeply dipping joint set that trends northeast-southwest. This joint set has <br /> only been observed in highwalls at the South Quarry and has an average plane of 85, <br /> 318. <br /> • A A moderately steep joint set with a northwest-southwest trend. The average <br /> plane for this joint set is 70, 30 in the South Quarry and 50, 51 in the West Quarry. <br /> The friction angle used for the kinematic evaluation was obtained from previous studies <br /> using direct shear test performed on trimmed (sawcut) core samples obtained from the South <br /> Quarry. These tests were performed as part of a lab testing program that included testing <br /> foliations, open fractures, and saw cut joints, and are shown in Table 4-1 and Table 4-2. A <br /> total of 23 direct shear tests were performed and the average of all tests showed a friction <br /> angle of 25 degrees and 50 psi apparent cohesion. A conservative friction angle value of 20 <br /> degrees 0 apparent cohesion was selected for use in the kinematic analyses. <br /> Planar failures occur when a plane of weakness (such as a joint) daylights in a slope at an <br /> angle steeper than the angle of friction of the joint surface and when the angular range <br /> between the strike of the potential failure plane and the angle of the slope face (termed lateral <br /> limits) are less than about 25 to 35 degrees. Wedge failures can occur when joints within the <br /> cut slope intersect and their line of intersection(termed plunge line) daylights in the slope <br /> and plunges at an angle steeper than the friction angle of the joints. In these cases, unstable <br /> "wedges" of rock can slide out of the rock cut slope into the quarry or onto a bench. Flexural <br /> toppling can occur when planes (joints) can slide with respect to each other, ultimately <br /> leading to flexure and breaking off rock slabs that can fall or topple out of the rock face. <br /> Direct toppling can occur when two joint sets intersect to form discrete blocks with plunge <br /> lines dipping into the slope and a third low angle joint acts as a release plane (or sliding <br /> plane) for the discrete blocks, allowing them to fall out of the slope. <br /> 2s <br /> Aggregate Industries—Morrison Quarry GEI Consultants, Inc <br /> AM-07 Geotechnical Stability Exhibit November 2020 <br />