Laserfiche WebLink
M98177GE <br />Factors <br />f generally <br />{ force) on <br />the soil. <br />that have an adverse influence on slope stability can <br />be classified as those that increase the stress (driving <br />the system or decrease the strength (resisting forces) of <br />Our stability analyses of the site slope soil material was based <br />on the Bishops method of slices. This method is based on the <br />assumption that the slope soil mass will fail in a rotation mode on <br />a circular arc plane. In this method of analysis the mass of soil <br />is divided into vertical slices. The forces acting on each slice <br />are evaluated from the equilibrium of the slices; that is, the <br />forces that tend to drive the slice downhill and the forces that <br />tend to resist the movement of the slice. The equilibrium of the <br />entire mass is determined by summing the driving and summing the <br />resisting forces acting on all slices and comparing these forces. <br />Our slope stability analysis was performed using "Slope Stability <br />Analysis" by Geosoft computer software. Our slope stability <br />analysis considered three (3) cross sections with a total of about <br />2,000 separate possible failure surface iterations to help identify <br />the potential theoretical slope stability. Our discussions and <br />data presentation is based only on the calculated critical circle <br />which presented the lowest factor of safety against failure. Our <br />presentation does not include the results of all of the iterations <br />which resulted in a theoretical factor of safety greater than the <br />lowest factor of safety and therefore were not critical. <br />Our analysis was based on soil strength characteristics obtained <br />from laboratory triaxial shear strength tests of samples of soil <br />material encountered in our test borings obtained during our field <br />study. The soil strength values used in our analysis included: <br />Site soil material: <br />an internal angle of friction of thirty (30) degrees, <br />cohesion of two-hundred seventy-five (275) pounds per square <br />foot and <br />a moist unit weight of one-hundred twenty-five (125) pounds <br />per cubic foot. <br />All areas to receive fill material should be stripped of all <br />vegetation, organic soil materials and other deleterious material <br />prior to fill placement. Areas to receive fill material should be <br />constructed with a toe key and benched into competent foundation <br />material. The key and bench concept is shown on Figure 3. <br />I <br />Lambert ana ~.sgnriates <br />CONSULTieG GEOTEONNiCAt ENGwEE RS AND <br />YATEAUI 1 ESTiNG <br />