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- 16 - <br />section in soils is shortened; this solution would increase the <br />height of the portal cut. Potential stability problems related <br />to a high portal cut might be severe if the cut.is close to the <br />steep slope above the bench. <br />The tunnels can significantly contribute to dewatering the <br />area behind the portal. However, if they were fully lined with <br />an impermeable liner, they would not function as drains. We <br />recommend that provisions for drainage into individual tunnels <br />are made so that effective drainage of the area can be enhanced. <br />It can be expected that the tunnels will practically replace <br />the drainage systems which would be installed earlier. <br />3.3 ACCESS ROAD <br />The proposed access road below the mine bench will be con- <br />structed partly within the landslide area. The design and con- <br />struction of the section within the landslide have been di- <br />cussed on numerous occasions with the representatives of Merrick <br />and Company. We have recommended that the necessary earth work <br />be kept to a minimum so that high cuts or fills are avoided. This <br />is difficult within the road section immediately below the pro- <br />posed bench where the road alignment traverses a steep natural <br />slope. <br />Because of the steep slope gradient, cuts or fills cannot <br />be constructed without appropriate retaining structures; it can <br />be expected that soil thickness on the order of 20 feet or more <br />will be encountered, and soil cuts are not feasible. <br />A typical cross-section of the road within this section <br />zaill include a cut supported by a retaining wall and a fill <br />:supported by another retaining wall. In order to evaluate the <br />stability of such a cross-section, we have performed several <br />stability analyses assuming the same soil properties as those <br />aw~roaocoKwuw nc <br />