2014-05-02_REPORT - M1974004

• Permit No: M1974004
• IBM Index Class Name: REPORT
• Doc Date: 5/2/2014
• Doc Name: Stability analysis of spec agg quarry
• From: Martin Marietta Materials
• To: DRMS
• Email Name: PSH
• Media Type: D
• Archive: No

Martin Marietta Materials
Spec -Agg 2014 Annual Report
6.3
Table 2: Representative Quarry Wall Orientations
New Wall Designation
Former Wall Designation
Slope Angle(,)
Slope Direction of Wall (z)
East Wall 1
East Wall
45°
242°
East Wall 2
(not considered)
45°
270°
Northeast Wall 1
Northeast Wall
35°
175°
Northeast Wall 2
(not considered)
45°
225°
Northeast Wall 3
(not considered)
45°
176°
Northwest Wall
Northwest Wall
35°
151 °
West Wall 1
West Wall
45°
091,
West Wall 2
West Wall
45°
120°
West Wall 3
West Wall
45°
091 °
Southwest Wall 1
Southwest Wall
45°
016°
Southwest Wall 2
Southwest Wall
45°
036°
South Wall
(not considered)
45°
000°
Southeast Wall
Southeast Wall
45°
335°
Notes:
1: Slope angles are measured relative to the horizontal.
2: Slope orientations are presented as dip directions measured from true north (0 °).
Friction Angle
A representative angle of friction (0 + i) = 330 was used for our kinematic analysis, where "0" is the basic
friction angle and 'T is the surface roughness angle (Hoek and Bray, 1977). The surface roughness
angle is the angle between the basic plane of the joint and the planes representing the surface of ripples
or undulations of the joint surface. This value was based on the results of the direct shear testing
performed as part of the 2003 geotechnical investigation (L&A, 2003). The test results produced only a
basic friction angle, 0, and results indicated that the basic friction angle of the discontinuities ranged from
13.70 to 49.30 with a mean value of 280. These results do not include the two direct shear tests
conducted on samples with clay material along the foliation plane, which produced an average friction
angle of 50. The surface roughness angle, 'T, has been estimated to be 50; this roughness angle has
been utilized for all of stability analyses since 1997.
6.4 Kinematic Analysis
We performed kinematic slope stability analyses for each of the representative quarry wall orientations
presented in Table 2. The analyses were performed to evaluate potential rock slope failure modes
controlled by planar rock mass discontinues based exclusively on the geometric relationships of the
discontinuities measured. Potential rock slope failure modes include sliding of wedges formed in the
slope by the intersection of two discontinuity planes, sliding of rock blocks along a single planar
discontinuity, and toppling rock blocks. The computer program DIPS 6.008 (Rocscience, 2013) for
Windows was used for the kinematic stability analysis. Inputs for the program include the following:
March 31, 2014 Page 10 Lachel & Associates, Inc.
Project 13364013 00 02014 All Rights Reserved