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GRAND JUNCTION <br />LINCOLN DeVORE, Inc. <br />GEOTECHNICALENGINEERS-GEOLOGISTS <br />1441 Motor Sc TEL: (970) 232-8968 <br />Grand Junction, CO 81505 FAX: (970) 242-15fi1 <br />Balaz & Associates <br />1005 N. 12"' St., Ste. 211 <br />Grand Junction, CO 81501 <br />Re: Preliminary Slope Stability <br />Conger Harvesting Area, Marble, CO <br />November 29, 2000 <br />At the request of Mr. Bill Balaz of Balaz & Associates, Inc. of Grand ]unction, CO, a preliminary <br />slope stability study at the Conger Harvesting Area has been performed. This preliminary slope <br />stability study considers both the original slopes at the site, as represented by a topographic map, <br />Balaz & Associates, Inc., Exhibit E, 1-24-98. No subsurface exploration on this site has been <br />performed by Grand Junction Lincoln DeVore nor is any information relating to the subsurface <br />soils and rock profile available. <br />Information regarding the surface and subsurface materials on this site which have been utilized <br />for this preliminary slope stability study include, but are not limited to the geologic map of the <br />Marble Quadrangle, U.S.G.S. Map GQ-512, 1966, the engineering geology factors, Marble area, <br />CO, CGS, 1972, letter report by Mr. Joe Hershey, CEI, prepared for the Gallegos Corporation <br />for this project, 12-20-97 and literature and previous geologic and geotechnical studies in the <br />Marble area performed by Lincoln DeVore, Grand Junction, Glenwood Springs and Gunnison, <br />1974 to 1992. <br />At our request, Mr. Bill Balaz prepared four cross sections of the harvesting area. We have <br />analyzed these cross sections and utilized section N-3 for this study. This particular section <br />includes the steepest natural slopes encountered on this site, the longest run of slope upon which <br />this site is included and the upper slopes in the future harvesting area were judged to be <br />representative of the majority of this project. <br />Slope stability calculations wc~c performed on the existing natural slopes and the proposed final slopes after <br />rock extraction has been completed, as best understood by Grand Junction Lincoln DcVorc. The stabllih <br />anah•sis addressed the individual slope and the `global ~ condition of [hc court embankment. The anahsis ~~as <br />performed using [hc PC software SLOPE/W. Version 4. Gco-Slope International LTD, Calgan. Alberta, <br />Canada. The analysis utilized the Limit Equilibrium Theon• for the factor of safety, incorporating 4 methods. <br />Fellenius or Ordinary Method = Moment Equilibrium <br />Bishop Simplified Method = Moment Equilibrium <br />lanbu Simplified Method = Force Equilibrium <br />Morgenstern-Price Method = <br />Moment and Force Equilibrium <br />