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?J <br />C. <br /> <br />TELEPHONE CONTACT REPORT <br />WITH: <br />-Name: Bob Huzjak <br />Title: Senior Project Manager <br />Company: GE! Consultants, Inc. <br />:address: 690 S. Potomac Street, Suite 200 <br />Citv:. Englewood, CO 80112 <br />Telephone Number: 303-662-0100 <br />Fax Number: 303-662-8;'67 <br />e-mail -Number: rhyzjak@jeicorsultants.com <br />TAKEN BY: Byron G. Walker <br />PER-MIT NUMBER: C-1996-083 <br />ACTION: Geotechnical Data Report Bruce Park Dam, April 2001 Project 99292 <br />DATE: 11 December 2002 <br />DISCUSSION: 2),Ir Huzjak called in response to a request for explanation of parts of the subject <br />report. The request was made by Walker to Jim Stover of Jim Stover and Associates. The factors of <br />safety in the pseudo-static analysis - main dam (Appendix B) are regression analyses to determine <br />the magnitude of horizontal accelerations required to reach imminent failure (factor of safery of one) <br />in the materials at various depths. This information is then plotted against anticipated magnitudes on <br />Figure 3.4 of the Geotechnical Evaluation of Mine-Induced Seismicity on Bruce Park Dam. Average <br />maximum acceleration anticipated is about half that of vield accelerations, the conclusion being that <br />the dam structure is safe from failure due to mine-induced seismicity. Traditional factor of safety <br />values are not appropriate to this type.of analysis as magnitudes of deformation are addressed, not <br />failure. <br />This issue was revisited by telephone on Monday, December 16, 2002. With reference to Rule <br />4.05.9(8)(a), Walker asked Huzjak (coordinated with Stover) to develop the Pseudo-Static Analyses <br />of Appendix B of the report with a factor of safety of 1.2, and to then compare the Yield <br />Acceleration and Average Maximum Acceleration of Main Dam. Figure 3.4, with the anticipated <br />mine-related averaJe maximum acceleration against the yield acceleration (1.2 in lieu of 1.0 factor of <br />safety). Such a demonstration would be conservative, as onl« deformation, not failure, is defined. <br />as, other state-of-the-art demoriz ration of a 1.2 factor of safety (failure) would also be considered. <br />DISTRIBUTION: <br />Cc: Robert J. Huzjak <br />J. E. Stover