STABILITY ANALYSIS OF MINE PIT SLOPES IN INTERIOR ALASKA

摘要

The Department of Mining and Geological Engineering at the University of Alaska Fairbanks was asked by a local mining company in mid 1990s to assess the potential slope instability problems on the Ryan Lode property at Ester near Fairbanks, Alaska. The geological discontinuity and groundwater information was obtained through a field program. The factor of safety of an example pit slope in the future Ryan Pit was determined using the limit equilibrium methods for plane and wedge failures, Sarma's method, and the local minimum factor of safety method. The shear strength parameters, c and phi, were estimated based on the first derivative of the maximum shear strength (tau_(max)) of rock mass with various degrees of quality. The analysis indicated that the example pit slope would have an overall safety factor above 1.0, under most of the conditions analyzed. However, the slope with RMR=14 would become critical, if water filled the crack.