Laserfiche WebLink
The fill material x111 be cut and backfilled from the outer edge - <br />of the end sting mine bench to establish desired configuration. The <br />material is composed of grey to dark grey shale, carbonaceous shale <br />partings and medium grained sandstone. All material to be used Trill <br />be derived from the Menefee Formation <br />EMPLACEPLLrKf~ <br />The fill x111 be emplaced by bulldozer, front-end loader and Sf' <br />necessary a sheep's foot roller. <br />STABILITYi <br />The highrdll x111 be stable as roposed. The resulting backfill x111 I ~ ° ~'? ~ ' ' ~'~ <br />have an average slope of 2~1 (22.5°~ and a maximum height of 29 feet. <br />Stability xas'determined from Terzaghi's formula i <br />Stability (C )= reaistinig force <br />driving force <br />When <br />G less than 1 = unstable slope, <br />C greater than 1 = stable slope, <br />C equals 1 = slope in equilibrium. <br />Resisting force is equal to the xeight per lineal foot times <br />the coefficient of friction of the material in question. <br />R h Z l x x x coefficient of friction <br />Where R = resisting force, resiatance~ foot of length <br />h = verticle height of resisting force, <br />1 = length to toe of fill, <br />x = weight of fill ~ foot of length , <br />Driving force is derived from Rankine/'s formula: <br />P= (.5) x x x h2 x I 1~ Sin 0} <br />Where P = driving force, pressure foot of length, <br />x = xeight of fill ~ cubic foot, <br />h = height of fill ; <br />0 = angle of repose of material. <br />r~-A~ ON <br />7 <br />(2) <br />