Similarity Test and Numerical Simulation on Deformation Failure of an Open-pit Slope under the Influences of Mining

Abstract

Underground mining significantly influences open-pit slope stability and threatens the overall slope safety as well as field safety production. This study discussed stress transfer characteristics in underground mining and the corresponding open-pit slope stability by combining a similarity model test and a numerical simulation on the Anjialing open-cast mine in Pingshuo, Shanxi. Thus, the position of terminal mining line was determined reasonably. The similarity model and numerical simulation results demonstrated that horizontal displacements of the slope free faces were approximately 2.2 and 2.3 m when the 29210 working face advanced to places 419 and 364 m away from the slope foot. The crack between the first and second steps of the slope was cut through and extended to downward steps when the working face approached the designed terminal mining line. As the working face advanced for another 60–120 m, the crack reached the slope foot and the upper steps rolled out. The reasonable terminal mining line 2 (364 m away from the slope foot) was the appropriate position to stop mining. Numerical calculation results were in high accordance with similarity model results. These research results have great significance in guiding the safety of open-pit mining.