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Martin Marietta Materials <br />Spec -Agg 2013 Annual Report <br />Table 2: Representative Quarry Wall Orientations <br />New Wall Designation <br />Former Wall Designation <br />Slope Angle(,) <br />Slope Direction of Wall (Z) <br />East Wall 1 <br />East Wall <br />45° <br />242° <br />East Wall 2 <br />(not considered) <br />45° <br />270° <br />Northeast Wall 1 <br />Northeast Wall <br />35° <br />175° <br />Northeast Wall 2 <br />(not considered) <br />45° <br />225° <br />Northeast Wall 3 <br />(not considered) <br />45° <br />176° <br />Northwest Wall <br />Northwest Wall <br />35° <br />151° <br />West Wall <br />West Wall <br />45° <br />091° <br />West Wall 2 <br />West Wall <br />45° <br />120° <br />West Wall 3 <br />West Wall <br />45° <br />091° <br />Southwest Wall 1 <br />Southwest Wall <br />45° <br />016° <br />Southwest Wall 2 <br />Southwest Wall <br />45° <br />036° <br />South Wall <br />(not considered) <br />45° <br />000° <br />Southeast Wall <br />Southeast Wall <br />45° <br />335° <br />Notes: <br />1: Slope angles are measured relative to the horizontal. <br />2: Slope orientations are presented as dip directions measured from true north (0 °). <br />6.3 Friction Angle <br />A representative angle of friction (� + i) = 33° was used for our kinematic analysis, where "0" is the basic <br />friction angle and '7' is the surface roughness angle (Hoek and Bray, 1977). The surface roughness angle is <br />the angle between the basic plane of the joint and the planes representing the surface of ripples or <br />undulations of the joint surface. This value was based on the results of the direct shear testing performed as <br />part of the 2003 geotechnical investigation (L &A, 2003). The test results produced only a basic friction <br />angle, 0, and results indicated that the basic friction angle of the discontinuities ranged from 13.70 to 49.3° <br />with a mean value of 28 °. These results do not include the two direct shear tests conducted on samples with <br />clay material along the foliation plane, which produced an average friction angle of 5 °. The surface <br />roughness angle, '7', has been estimated to be 50; this roughness angle has been utilized for all of stability <br />analyses since 1997. <br />6.4 Kinematic Analysis <br />We performed kinematic slope stability analyses for each of the representative quarry wall orientations <br />presented in Table 2. The analyses were performed to evaluate potential rock slope failure modes controlled <br />by planar rock mass discontinues based exclusively on the geometric relationships of the discontinuities <br />measured. Potential rock slope failure modes include sliding of wedges formed in the slope by the <br />intersection of two discontinuity planes, sliding of rock blocks along a single planar discontinuity, and toppling <br />rock blocks. The computer program DIPS 6.008 (Rocscience, 2013) for Windows was used for the kinematic <br />stability analysis. Inputs for the program include the following: <br />April 22, 2013 Page 11 Lachel & Associates, Inc. <br />Project 12361005.00 ©2013 All Rights Reserved <br />