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Martin Marietta Materials <br />Spec -Agg Project <br />5.0 ANALYSIS OF STRUCTURAL DISCONTINUITIES <br />The stability of the rock mass that forms the highwalls of the quarry is mainly controlled by the <br />discontinuities. Discontinuities create the surfaces that sliding can occur upon and the intersections of <br />multiple discontinuities define the boundaries of wedges or blocks that have the potential to slide. As <br />observed throughout the quarry, the discontinuity sets all have a range of dip and dip direction, and therefore <br />it is possible that discontinuity orientations in a specific location of the quarry deviate locally from the general <br />discontinuity orientations assumed for the analyses presented in this report. <br />5.1 Evaluation of Discontinuity Measurements <br />As the database for discontinuity measurements has increased, various methods have been utilized to <br />efficiently analyze the new acquired geologic data. The analysis of the discontinuity data was conducted <br />using DIPS 5.1 (Rocscience, 2006), which is an software program for the analysis of discontinuity <br />orientations based on geological data inputs. For this study, the data were evaluated with stereographic <br />plots using a combination of contour analyses and cluster analyses to determine representative dip <br />directions and dip angles for the predominant discontinuity sets. <br />The contour analysis of the entire dataset (i.e., 3108 points) resulted in a plot of density contours, which has <br />in the past facilitated our determination of the general discontinuity orientations across the entire facility <br />(Figure 6). The cluster analysis has helped to further refine the data by utilizing an iterative approach to <br />group the data measurements into representative clusters. The nucleus of each cluster represents the <br />concentration center for a given data set as is shown for the cumulative dataset (i.e. 3108 points) in Figure 6. <br />The differences between past individual year's analyses can be seen on a stereographic presentation <br />showing each of the concentration poles for the clusters for each annual analysis, but due to the overall <br />small sampling of datapoints for the past several year's investigations, data for 2007 -2012 have been <br />combined (Figure 7). A combination of the clusters from Figure 7 and the results of the contour and cluster <br />analysis of the entire dataset (Figure 6) were used to define the discontinuities and their orientations for use <br />in this year's analysis. These poles are summarized in Figure 8 and are presented in further detail in Table 2 <br />below. <br />February 13, 2012 <br />Project 11361017.00 <br />Table 2: Representative Discontinuity Orientations <br />Concentration <br />Center <br />Dip Direction /Dip <br />2011 Results <br />2012 Final Results <br />(3,108 Points) <br />F -1 (Fol) 168 ° /34° 170 ° /33° <br />F -2 (Fol) 198 ° /24° * 198 ° /24° <br />F -3 (Fol) 294 ° /36° * 294 ° /36° * <br />P -1 (Joint) 172 ° /74° 172 ° /74° <br />P -2 (Joint) 087 ° /58° 095 ° /62° <br />P -3 (Joint) 257 ° /66° 255 ° /67° <br />P -4 (Joint) 296 ° /72° 296 ° /72° <br />P -5 (Joint) 353 ° /67° 353 ° /67° <br />P -6 (Joint) 025 ° /57° 025 ° /57° <br />* Derived from previous years analysis <br />Page 8 <br />Lachel & Associates, Inc. <br />©2012 All Rights Reserved <br />