Laserfiche WebLink
SEP-9-2004 15: 1B FROM: BILL & JRNE JRNKE 1-970-72B-6315 T0: 19702475104 P.9 <br />Mr. Bill Jatike <br />December 23, 2002 <br />Page 3 <br />overburden stress equivalent to approximately 15 feet depth. The critical <br />shear surfaces that pass tluough the embankment slope extend as deep as 50 <br />feet. <br />W <br />7. The samples selected for direct sheaz testing came from as deep as 50 feet <br />and when tested at the low normal stresses (as discussed above under <br />Comment 6) are effectively over-consolidated. This will result in higher <br />measured shear strengths than exist in the slope. <br />R. The actual slope as Indic^ted by the Foley sur<~ey sho~.~,n or. Sheet 2 of 4 is <br />significantly steeper than the slope modeled in the Pinnacle slope stability <br />analysis. The Foley topography indicates that the overall slope has been <br />constructed at about 1.Sh:ly, while the Pinnacle slope model is about <br />2.2h:1v. The steepness of the slope is fundamental [o analysis of the stabil- <br />ity of the slope. It appears that the Pinnacle slope stability analyses should <br />have incorporated the steeper slope which would result in calculation of <br />lower factors of safety. <br />Technical opinions presented in this report are based on review of <br />documents provided; our experience in the field of slope stability analysis and risk <br />assessment, and past experience with similar conditions. The conclusions and <br />recommendations presented in this repots are subject to the limitations and explazia- <br />tions contained herein. No other use is intended or implied by the information, <br />opinions, conclusions and recommendations contained herein. <br />Please call if you have any questions or would like to discuss these <br />comments. <br />Sincerely, <br />MICHAEL W. WEST & ASSOCIATES, INC. <br />By: Peter A. Stauffer, P.E. <br />Senior Geotechnical Engineer <br />