2023-08-03_PERMIT FILE - M2023025 (29)

Home Browse Search

SLOPE STABILITY RESULTS When estimated soil strength parameters are used, the MLRB requires minimum safety factors of 1.50 for static condition analyses and 1.30 for pseudo-static (earthquake loading) condition analyses for embankments adjacent to critical structures. The calculated factors of safety are within the design criteria specified for this project and can be considered indicators of the mining slope performance under the various conditions. The results of the static condition and pseudo-static condition slope stability analyses are shown in Tables 2, 3, & 4 below. Table 2: Mining Conditions Static Condition Slope Stability Analysis Results Required Calculated Minimum Factor Factor of Description of Safety Safety Case SS-1 — Gas Line West of Pit— Static 1.92 1.50 Case SS-2 — Gas Line North of Pit— Static 2.14 1.50 Case SS-3 — Gas Line Northeast of Pit— Static 1.96 1.50 Case SS-4— Gas Line East of Pit— Static 1.91 1.50 Case SS-5 — Gas Line South of Pit— Static 1 1.88 1 1.50 Table 3: Mining Conditions Pseudo-Static Condition Slope Stability Analysis Results Required Calculated Minimum Factor Factor of Description of Safety Safety Case SS-1 — Gas Line West of Pit— EQ 1.53 1.30 Case SS-2 — Gas Line North of Pit— EQ 1.55 1.30 Case SS-3 — Gas Line Northeast of Pit— EQ 1.52 1.30 Case SS-4— Gas Line East of Pit— EQ 1.52 1.30 Case SS-5 — Gas Line South of Pit— EQ 1.51 1.30 Table 3: Reclaimed Conditions Static & Pseudo-Static Condition Slope Stability Analysis Results Description Calculated Required Factor Minimum Factor of Safety Of Safety Case SS-5 — Gas Line West of Pit— Static 2.28 1.50 Case SS-5 — Gas Line West of Pit— EQ 1.62 1.30 The Galena analysis output files are included in Appendix C for all cases. IHC Scott,Inc.—Bernhardt Sand and Gravel Pit '7 Slope J&T Consulting, Inc. pe StabilityA Page/4