_GENERAL DOCUMENTS - C1981017 (319)

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Plan C- Cut Slope Unstable In November of 1983, a geotechnical assessment was done of the entire road system by Geo-Hydro Consulting, Inc . In this report , potential areas of instability on the cut slopes were identified . Where possible, any fill material dug from low water crossings should be used to shore up these cut slopes . An example of this work is shown on Cross-Section C. The maximum angle that the material should be placed is 2 . OH : 1 . OV . Using the geometry shown in this cross-section and a friction angle of 45` , a density of 105 1 bs/cu . f t . , a cohesion of 700 psf and a pore pressure ratio of 0 . 5 , the slope safety factor for this fill is 5 . 25 . The following items are guidelines for the entire road reclamation process . Using these guidelines , it is proposed that the roads are reclaimed after field verification on a case by case basis . 1 ) In both reclamation cases , road access is maintained although the entire road surface will be loosened , seeded and mulched . 2) Water must be delivered across the surface to the fill slope in a stable way in order to minimize erosion and future maintenance. For Plan A , the inside ditch should outlet to low water crossings wherever possible. Culverts would be removed unless the outlet was installed so far down the fill slope as to make their removal impractical . In this case, they will be plugged . In some major drainage crossings , it is impossible to remove the huge culverts and maintain access . In these areas , all reasonable steps will be taken to make the crossing as stable as possible. For Plan B , low water crossings will also be employed as the preferred method of water transfer , but they will be less frequent since water is being delivered across the road surface over its entire length . Low water crossings will be used f or uph i 11 dra i nage cross i ngs . As i n P 1 an A, cu 1 verts can be removed or plugged and major drainage crossings must remain intact .