Sensitivity analysis of stability factors of goaf based on numerical simulation orthogonal test

The stability of goaf is restricted by variety of factors, determining the sensitivity of each influencing factor is very important for determining the unstable main control factors of complex goaf, and it is important for establishing the comprehensive evaluation system of goaf.Uniaxial compressive strength, RQD, joint spacing, groundwater, Poisson ratio, height of goaf, area of goaf, cover depth, length-width ratio of goaf are as analytical factors in the paper.Based on orthogonal design and numerical simulation method to determine “9 factors, 4 levels” experiment schemes, the factors of rock mass are converting into rock mechanical parameters by the criterion of Hoek-Brown.The experimental results are analyzed with total volume of plastic zones, the volume of roof-plastic zone, the volume of side wall-plastic zone as an assessment indicators, it is show that the cover depth of goaf, the area of goaf, uniaxial compressive strength, and length-width ratio of goaf are the most sensitive to the stability of goaf.Which is theoretical guiding significance to the determination of the weight value of factors in stability assessment of goaf and designing stope size in production.