Laserfiche WebLink
<br />Donald A. Crane Page 3 <br />`• regarding water table position (condition No. 4) and regardless of the <br />configuration, the factor of safety is greater than 1.6. <br />The following cases were analyzed and reported: <br />1. ColoWyo configuration with a colluvium 0 of 26 degrees and a spoil 0 <br />of 35, 37, and 39 degrees, spoil density 115 pcf. <br />2. ColoWyo configuration with a colluvium 0 of 40 degrees and a spoil 0 <br />of 35, 37 and 39 degrees, spoil density 115 pcf. <br />3. OSM configuration with a colluvium 0 of 26 degrees and a spoil 0 of <br />35, 37 and 39 degrees, spoil density 115 pcf. <br />4. OSM configuration with a colluvium 0 of 40 degrees and a spoil 0 of <br />35, 37, and 39 degrees, spoil density 115 pcf. <br />5. Co1o[Jyo configuration with spoil density of 105, 125, 105 pcf and <br />colluvium 0 of 26, 40 degrees, (4 combinations) respectively, spoil 0 <br />37 3egrees. <br />6. OSPI configuration with spoil density of 105, 125 pcf, and colluvium 0 <br />of 26 and 40 degrees (4 combinations), spoil 0 37 degrees. <br />7. Colo[Jyo configuration with spoil 0 of 37 degrees, and density of 115 <br />• pcf, colluvium 0 26 degrees, and four water table locations. <br />8. ColoWyo configuration with spoil 0 of 37 degrees and 3ensity of 115 <br />pcf, colluvium 0 40 degrees, and four water table locations. <br />The lowest factors of safety, 0.87, were calculated for "case" 7 above using <br />the highest (a condition considered to be unlikely for the fill) water table <br />conditions. Using on'_y the water tabie condition No. 4*, considered by the <br />Contractor to be the most reasonable for the site, the lowest factor of safety <br />calculated was 1.58. <br />The calculations show OSM "designs" to have equivalent stabilities to the <br />CololJyo design. If the OSP1 design is cut back co approximate the top of the <br />Colo[•7yo design about the 6,900 foot evaluation, stability may be slightly <br />higher. It can be concluded that there are essentially no differences in <br />overall stability of the two fill designs. OSM's design would not produce a <br />higher factor of safety than the 1.58 calculated for the CololJyo design at <br />water table conditions No. 4 (lowest degree of saturation). <br />The consultant concludes from these analyses that: <br />"1. The results of analyses indicate the most critical variables are the <br />strength of the underlying colluvium and the location of the free <br />water table. <br />• "2. Considering the results of the analyses, it appears a factor of safety <br />~in the range of 1.6 to 1.8 is appropriate for the most probable <br />conditions for the CololJyo spoil pile." <br />ontractor state [ s coo t on o. , even :oug> >e m 5 , <br />was only "remotely probable" since, in their opinion, "the spoil cannot become <br />saturated" (pp. 12 and 13). <br />