Abstract：It is very difficult for theoretical analysis and field observation since the movement and bed separation characteristics of overburden strata above mine voids induced by underground mining is a very complicated problem，which influenced by many factors，and the deformation and movement of overlying strata are not visible and touchable. In this paper，the movement and failure process of strata induced by underground mining are numerically simulated by using the rock failure process analysis code(RFPA2D) to investigate the height of bed separation development，the location of the bed separation zone and the effect of the extracted thickness of the coal seam on the development height of bed separation. Numerical simulations demonstrate the whole process of mining induced strata movement and the characteristics of bed separation，furthermore，the relationship between the height of bed separation and the advance distance of coalface，the effect of the extracted thickness of the coal seam on the development height of bed separation are indicated. Numerical results offer important theoretical basis and reliable evidence for the determination of the location and scale of the bed separation zone wide application of the technique of grouting into the separated strata to control the surface subsidence.
