Constitutive Model Of Joint Rock Mass Damage Due To Mining And Its Application In Engineering Of Open-underground Combined Mining

The rock mass of open pit slope is primary damage mass with large mount of joints. The primary damage will evolve after mining under the slope if open-underground combined mining is carried out. By joint statistics on the spot and geometry damage theory, this dissertation established a probability model of joint damage tensors and applied VC++ to developing it into a Mohr-Coulomb constitutive model of joint elastic-plastic damage on the basis of plastic flow format in FLAC^3D. Based on this model, a numerical model of mining under the South Slope and West Dumping Slope of Anjialing Mine in Pingshuo Mine Field was set up for further research. Subsidence and distortion rules of slope bench surface which is different from ordinary surface were researched. Surface movement observation data provided parameters for mining subsidence forecast. Point safety degree formula in Modified Mohr Failure theory was applied to obtaining zone safety degree distribution of the model and stability status of slope. Different mining schemes were compared in plastic areas and displacement of slope rock mass so as to put forward rational mining suggestions for the safety of slope.