Paper Title
Derivation of Empirical Equations for Determination of Safe Pit Slope Geometry at Phukham Mining

Abstract
Objective of this study is to investigate rock shear strength parameters of fault and shear zone at South Wall of Phu Kham open pit mine by direct shear testing. The test results are simulated in numerical models using distinct element method (UDEC code) under different slope faces and angles and shear strength parameters. The model results indicate that the safety factors of slope increase with increasing cohesions, friction angels and distances between fault and slope face, but decreases with increasing slope face angles. An empirical equation is derived here using the simulation results. It can be used to predict the safety factor of slopes under various slope face angles, cohesions and friction angles of the hanging wall. Distances between fault from crest are not derived in equation because they are not sensitive to the factor of safety. Keywords - Slope Angle, Fault, Friction Angle