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i <br />-6- <br />~~ <br />_~ <br />1~ <br />~j drainage is provided. Residual strength values for compacted soils were <br /> <br />i used in our analyses: We believe that these values are conservative. <br />r <br />.. CUT SLOPE STABILITY ANALYSIS <br /> <br /> The regulations specify that cut slopes in rock be no steeper than <br />1i 0.25 horizontal to 1 vertical under Section 4,03.1 (3)(c). Bedrock was <br /> exposed at the ground surface in the areas where cuts will be <br />i <br />~ <br />required. The bedrock in this area is steeply bedded and has some <br /> discontinuities due to jointing. We analyzed cut slopes using <br />'~ stereographic methods described in the 2nd Edition of "Rock Slope <br /> Engineering", by E. Hoek and J. Rray, 1977. Markland's test was used to <br /> <br /> determine stable slope angles. A slope is considered "safe" provided <br />1 that the line of intersection of any two joint (or bedding) planes do <br /> not daylight on the surface of the slope with an angle greater than the <br />~ friction angle of the rock surface. The results of the analyses, shown <br /> on Figs. 5 and 6, indicate that cut slopes will be "stable" at slopes no <br /> steeper than 0.7:1 (horizontal to vertical) between Stations 3+00 and <br />' <br /> ' ~ ..- <br />4+00. Between Stations 8+DO and 10+00, cut slopes should be no steeper <br />.-, than 0.36:1. Periodic ravelling of the slopes can be expected due to <br />' weathering. <br />Our analyses indicate that varying cut slopes will be "stable" <br />depending upon the location of the cut. We recommend that cut slopes be <br />no steeper than 0.7:1 (horizontal to vertical) to reduce confusion <br />during construction and to develop borrow Soils for fill, Flatter <br />