Laserfiche WebLink
1 <br />' piezometers. Consequently, after obtaining safety factors for <br />Section C-C based on available PZ measurements, the piezometric <br />surface was remodelled to simulate the hypothetical piezometric <br />surface described earlier, which extends to or peaks at the surface <br />under the first slope bench. Though this remodelling can not, at <br />' this time, be considered an accurate representation of actual <br />conditions within the pile, the section was analyzed to check <br />stability in the event higher pore pressures are in effect. Two <br />' different searches were initiated for the remodelled section <br />including a search for the minimum safety factor and location of a <br />shear surface with a safety factor just less than 1.5. The <br />' profile, parameters used and resulting safety factors for <br />remodelled Section C-C are presented on Plate 12 in the Appendix. <br />The following table summarizes safety factor results obtained for <br />each of the critical sections: <br />' SAFETY FACTOR SUMMARY <br />' CRITICAL SURFACE <br />RADIUS POINT <br />SECTION SLOPE X COODR. Y COODR. RADIUS SAFETY 6 <br />FACE FRM. TOE (ELEV) (FT) FACTOR <br />' (FT) <br />A-A FRONT 402.00 5168.00 322.00 1.834 STATIC <br />' B-B FRONT 100.00 5527.00 704.00 1.587 STATIC <br />C-C FRONT 140.00 5435.00 604.00 1.781 STATIC <br />' C-C BACK 1060.00 5114.00 164.00 2.046 STATIC <br />C-C <br />' REMODEL FRONT 154.00 5091.00 260.00 1.499 STATIC <br />C-C <br />' REMODEL FRONT 161.00 4956.00 123.95 1.353 STATIC <br />CONCLUSIONS AND RECOMMENDATIONS: <br />' As can be seen from the above tabulation, if the stability is <br />evaluated based on the assumption that the highest water level <br />elevations encountered in the wells represents a phreatic surface, <br />' the pile slopes can be shown to exhibit adequate safety factors. <br />However, as has been previously discussed, there is a possibility <br />that higher pore pressures exist which are not reflected by the <br />' existing wells, simply because open-well type piezometers are not <br />capable of allowing pore pressure measurements in a zoned-aquifer <br />condition. Even though it appears to us that the assumption of a <br />' single phreatic surface based on the maximum indicated water levels <br />would possibly be conservative and the pile more likely than not, <br />satisfies stability requirements, a very real possibility also <br />exists that even higher pore pressures occur. The "remodelled" <br />' 17 <br />1 <br />