Determination Of Rock Mechanical Parameters On Numerical Simulation Of Mining Subsidence At No.1Coal Mine Of An Jialing

The determination of rock mass mechanical parameters is basic work fornumerical simulation. But the parameters’ selection is often quite difficult because ofthe complex quality of the rock mass. Based on the engineering background in AnJialing No.1coal mine, different kinds of methods of determining the parameters aresummarized firstly. Then, a proper scheme is given here.(1) Based on the geological conditions of the project, a three-dimensionalnumerical simulation model was established by ROCKModel software forFLAC3D4.0.(2) Determine the initial soil and rock mechanics parameters respectively. TheMohr-Coloumb yield criterion is used for soil and the soil parameters including thedeformation parameters(E、μ) and the strength parameters(C、φ) will be determinedthrough engineering analogy methods. The Hoek-Brown yield criterion is used forrock mass. In this paper, a method of combining the laboratory mechanical test resultswith GSI will be used to estimate the initial values of the rock mass mechanicalparameters, including deformation parameters(E、μ、σ ci)、Hoek-Brown constantm and s.(3) In order to obtain more precise parameters, the main mechanical parametersof rock masses will be determined by the back analysis in combination orthogonalexperiments with numerical simulations.Take the Maximum Surface Subsidence Coefficient (MSSC) as the test indicatorand the rock mass mechanical parameters as the experimental factors. Conduct aseries of numerical simulation schemes using FLAC3D4.0. Analyze the results bymeans of range analysis and variance analysis, and obtain the optimized rock massmechanical parameters.(4) Test the accuracy of the numerical simulation results using the optimized rockmass mechanical parameters.