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<br />w -7- <br />• <br />slopes may be desirable to increase the volume of borrow soils and for <br />ease of construction. <br />~ CONSTRUCTION RECOMMENDATIONS <br />Paragraph 4.03.1 (3)(d) of the regulations requires that fill placed <br />on slopes exceeding 1 vertical to 5 horizontal be keyed into the <br />L bedrock. While our analyses indicate that fill will be stable without <br />benching, we believe that proper construction and compaction of fills on <br />^ these steep slopes will require benching. We recommend the haul road be <br />l= constructed in accordance with the following recommendations: <br />~~ 1. Figure 7 presents a typical haul road cross-section. Cut <br />.• slopes should be no steeper than 0.7 horizontal to vertical. <br />Maximum fill slopes should be 1.5 to 1 (horizontal to <br />vertical). <br />~ 2. Benches should be excavated into the hillside prior to <br />L placement of fill. Benches should be at least 10 feet in width <br />with at least 1 bench for every 5 feet of elevation <br />_~. difference. Benches should extend through the weathered <br />' bedrock and be bottomed in relatively unweathered bedrock. <br /> 3. Fill should <br />conditioned be <br />to placed in thin, loose lifts, moisture <br />near optimum moisture content, and be compacted <br /> to at least 95 percent of maximum standard Proctor dry density <br /> determined in accordance with ASTM D 698 (AASHTO T-99). <br />T ~ ..- <br />I! 4. Fill should be free of debris or deleterious'substances. <br />•~ 5. The placement and compaction of fill should be observed and <br />tested 6y a qualified geotechnical engineer during <br />~1 construction. <br />Y . <br />SURFACE DRAINAGE <br />The control of surface drainage is important to the performance and <br />servicability of the haul road. We recommend that the surface of the <br />'. <br />