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accomplished, the "resisting" forces are divided by the "driving" <br />• forces, and the resulting number is referred to as the factor of <br />safety. Therefore, if the factor of safety is equal to 1,0, the <br />driving forces and resisting ~rces are equal and the slope would be <br />at a point of impending failure. A factor of safety of 1,0 then <br />wc:uld be considered as the point where slope failure occurs. A slope <br />which has a factor of safety of less than 1.0 theoretically would <br />fail. Slopes with factors of safety greater than 1.0 would theoreti- <br />cally be stable, with a degree of stability being dependent on the <br />amount b} which the factor of safety exceeds 1.0. <br />In keeping with "state-of-the-art" procedures, a factor of safety <br />of 1.5 is considered the minimum permissible factor of safety for <br />"stable" slopes. As has been previously mentioned, a factor of safety <br />• of 1.0 would indicate impending failure. Using these two points we <br />can divide slope stability into tt:ree broad categories: <br />1. Slopes w'.th factors of safety of 1.0 or less, which would be <br />unstable. <br />2. Slopes with factors of safety greater than 1.0, but less than <br />1.5, which would be in a condition of marginal stability. <br />3. Slopes with factors of safety of 1.5 or greater, which would <br />be considered as stable. <br />with these vaJ_ues and ranges in mind, we will continue the discussion <br />of slope stability analysis. <br />The slope stability analysis for this site was performed using a <br />limit equilibrium method of slices technique known as Spencer's Method. <br />The actual computation was done by computer. The program which was <br />• used is designated "SSTAB-1" and was developed by Steven G. Wright at <br />the University of Texas. An automatic search option was used for tt.e <br />