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~~ ~~ 82298/3 <br />Table I sivmnarizes the results of the computer analysis. <br />The unit weight of the material was varied based on the rela- <br />tive density chosen and whether the material was evaluated in <br />a dry state, wEat but not saturated state, and a saturated <br />buoyant condition. In addition, an earthquake loading accel- <br />eration factor of O.lg was introduced into two of the computer <br />runs. <br />Trial #4 consisted of the saturated buoyant tailings con- <br />dition and indicated a factor of safety of 1.04. A saturated <br />buoyant condition for the entire embankment is highly improbable <br />due to the free draining characteristics of the embankment <br />materials and the physical constraints of obtaining this type <br />of condition. Trial #1 consisted of the embankment materials <br />at 50 percent relative density and at a wet but not saturated <br />state. A relative density of 50 percent is the approximate <br />density which is obtained for tailings sands deposited hydrau- <br />lically with no additional compaction. A wet but not saturated <br />state models the free draining characteristics of the materials <br />and the utilization of the underdrain system. Trial #1 resulted <br />in a factor of :safety of 2.04. Trial #3 modeled a possible <br />small failure along the downstream face of the embankment with <br />the soils in a ciry state and at a 50 percent relative density, <br />A factor of safety of 1.62 was obtained. The earthquake analysis <br />was performed ot~ Trials #1 and #3. Although the factors of <br />safety were reduced to 1.59 and 1.28, respectively, the values <br />were still significantly above unity. <br />A sliding block analysis was accomplished to determine if <br />a potential failure situation could occur between the bottom <br />of the tailings embankment and the bedrock surface. Mr. Ponchak <br />