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steep sidehill sections. ' <br />Water is a major factor in most landslides. Fortunately, water was not <br />noted in holes associated with the road profile. Surface water runoff <br />will be controlled. Positive drainage will be maintained in areas of <br />both cuts and fills. Prior to construction, seeps will be noted in areas <br />of road construction. If a seep is located in an embankment area the <br />seep will be "developed." Blocking a seep builds up pore pressure which <br />eventually results in slope failure. Rock will be used to channel the <br />water from the seep and thrcugh the esnban]anent, generally called a <br />"French drain." Mirafi Corporation has specific guidelines for <br />construction of French drains in conjunction with using geotextile <br />fabric. At the present time the Seneca Mine has 16 rolls (8000 square <br />yards) of Marafi on hand to deal with unstable (soft) areas and <br />development of French drains. <br />Sta 0+00 to 35+00 <br />Minor cuts and fills will be made in this section of the alignment. <br />Stas. 0+00 to 27+00 are located on alluvial material mapped as Qal. <br />Stats. 28+00 to 35+00 are mapped as Kwfl and Kwft which is predominately <br />the Twenty Mile Sandstone units. Problems >n this area should be limited <br />to rockfall. Areas of noticeable unstable rock or potentially unstable <br />rock will either be fenced with a rock gabion fencing or the loose <br />material pulled down so as not to present a safety hazard. Cut slopes in <br />this area are designed at 1.5 h:lv. Fill slopes are designed at 3h:ly. <br />Slight adjustments to the centerline will be made to avoid either <br />• excessive cuts or excessive fills. Ditch slopes will be kept at a <br />positive gradient to maintain drainage and prevent ponding of water. <br />Sta 35+00 to 51+00 <br />This area was mapped as Kwfl, Kwft and Qf. As noted in the Ivey report, <br />this section of the road will be largely constructed in shale and <br />sandstone. The bearing of the alignment with respect to the regional <br />strike and dip of the rocks is favorable in this reach. Near Sta. 45+00 <br />a false fill will be constructed to carry the surface runoff from the <br />drainage above the fill around the fill section via a ditch. This was <br />done to keep the drainage from flviing into the pond and thus reduce the <br />volume of water and consequently pond size. Sancstone encountered during <br />road cut section construction could be placed it the bottom of this fill <br />to ensure no ponding of water and thereby eliminating saturation of this <br />fill. Cuts and fills in this section will have similar slopes to that <br />previously mentioned. <br />Sta. 51+00 to 64+00 <br />This section of the road presents the greatest potential for road <br />instability. The centerline traverses landforms that have been mapped as <br />Qsg? and Qug, questionably stable ground and unstable ground <br />respectively. Stability analysis were conducted at Stas. 51+00 and <br />60+00, chosen for their "typical" cross-section properties. These <br />cross-sections and resulting factors of safety are discussed in detail in <br />the Stability Analyses section of this report. The sidehill sections are <br />in an area <br />• 9 <br />