_REVISION - M1977347 (2) - Laserfiche WebLink

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J Holnam, Inc. 7erracon ELI Project No. 20945006 indicate the material to have an effective stress internal angle of friction of 32.3 degrees and a J total stress internal angle of friction of 34.3 degrees with a cohesion of zero when the material is compacted to approximately 85 percent of Standard Proctor Density ASTM D 398-78. Stability analyses were run using the above data and the PC slope program Version 5.0 developed by GeoSlope Program Ltd. of Calgary, Alberta Canada. The simplified Bishop metf~od and wedge methods of slope stability were utilized and run through the deepest section of the fill. Analyses were run on the anticipated dry state and for a worst case where water would be running through the fill at the bedrock surface. The factor of safety for the slope was determined to be 1 .7 in the dry state and 1.5 in the wet state using the simplified Bishop method. Based on the wedge analysis, the factor of safety in the dry state was determined to be 4.6 and in the saturated state, the factor of safety was calculated to be 3.9. Based on these analyses, it is our opinion the proposed load-out benches will tie stable. We further understand that the load-out benches will be vegetated. It is important that the benches be vegetated to minimize erosion. Sloping of the upper bench back toward the uphill slope will help direct drainage away from the embankment slope and will further help minimize erosion. It is recommended that adequate drainage be provided to direct surface water around the slope in all areas. J Earthwork: J • General Considerations: The conclusions contained in this report for the proposed J construction are contingent upon compliance with recommendations presented in this 1 section. • Site Clearing: Site clearing consists of removing all sandstone and limestor~e to the lower 1 sandstone tense at the base of the quarry. • Excavation: Excavation of the bedrock requires blasting. Blasting is currently being used I to break up and remove the overburden and to quarry the limestone. • Placement and Compaction: 1 . Place and compact fill in horizontal lifts, using equipment and procedures that will produce recommended densities throughout the lift. 2. Uncompacted fill lifts should not exceed 2 feet in loose thickness. 1 4