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rock cuts. The cutslopes and outslope were conservatively modeled at a 0.5:1 slope and a 1:1 <br /> slope, respectively. <br /> 3.4.2 Stability Analysis Results <br /> The stability analysis results are presented in Figures 4 and 5. They indicate safety <br /> factors of about 1.4 for the rock cuts, and over 2 for existing cuts in terrace deposits/colluvium. <br /> 4.0 Conclusions <br /> Based on the findings of the geotechnical investigation and stability analyses conducted, <br /> the following is concluded: <br /> • The cut-fill road section appears to be in cut, with fill placed over bedrock on the <br /> resulting bench and on the outslope. <br /> • The results of the stability analyses indicate a factor of about 1.4 for the rock cuts and <br /> over 2 for cuts in terrace deposits/colluvium. <br /> • The cuts in rock are steep but the rock is relatively strong, and the rock bedding is <br /> dipping favorably from a stability standpoint. <br /> • Occasional raveling of the cutslopes and minor rock falls will occur, especially during <br /> the spring snow melt, requiring road maintenance. <br /> • The new access road can be used for the purposes intended, provided the <br /> recommendations summarized in this report are incorporated during construction. <br /> 5.0 Recommendations <br /> 5.1 Cutslopes <br /> As described above, occasional raveling of the cutslope could occur. Accordingly, <br /> measures to protect vehicles and workers from potential rock falls should be considered. A <br /> formal annual inspection of the cutslopes should be performed by an experienced geotechnical <br /> engineer or engineering geologist, to check that the slopes are performing as anticipated. <br /> 5.2 Roadway Grading <br /> The road should be constructed in a manner that results in road grades of less than 18 <br /> percent. Fill slopes should be no steeper than 1.5:1. Between Stations 15+00 and 16+50, the <br /> roadway subgrade should be prepared by scarifying the upper 6 inches, moisture conditioning the <br /> scarified soils to within 3 percent of the optimum moisture content, and compacting to at least 95 <br /> percent relative compaction per ASTM D1557-09. Materials used as fill should be free of <br /> organic material, have a liquid limit and plasticity index less than 30 and 15, respectively, with <br /> the largest particle sizes less than six inches. Most onsite materials will be suitable for use as fill. <br /> Rule 6.5 Geotechnical Stability Technical Revision April 2,2012 <br /> New Access Road Page 5 <br />