Unformatted text preview: Sand Drain Effects of moment axis location on calculated factor of safety and melhod to establish mOst critical slip surface. o Choose another radius or staring point and repeat the FS contour map. o From a series of FS contour maps, identify a critical zone where FS is minimal. o Calculate the minimum safety factor for a slip circle centered in this critical zone. Typically require FSmin = 1.5. o Computer programs use a search technique to locate the critical zone. • Water Pressure by Flow Nets (use with method of slices) o Draw slope to scale and divide into slices o Construct tlow net with tlow lines and equipotential lines (they are perpendicular) ~-.. \ . ..... '/- FlowLines .. "(. . \ f .. \ \ \..-~ __ J,--~ Equipotential Lines , ,/1/1'_ ~~::;;'0>;r};;N;:~;.: l I I __ .J - - -----_.--_ ..----...
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- Fall '08
- Cartography, Topographic map, critical slip surface