Aiming at the practical situation about engineering geological conditions and productivity requirements of Xinshan ore block of Kafang mine

the optimization schemes of 3 feasible mining sequences are proposed based on the reconstructed mining environment idea. By using finite element analysis software MIDAS/GTS

a three dimensional finite element model of complex ore body is built. The mechanical time-varying effects of the 3 schemes are simulated and analyzed by numerical simulation. The results show that the stress and displacement of stope gradually increase and significant stress concentration appears as the advance of mining steps. In the 3 schemes

the maximum compressive stress is up to 27 MPa in the stope surrounding rock; to the roof

the maximum compressive stress is no more than 15 MPa and the maximum tensile stress of the roof reaches 1.2 MPa; for the subsidence displacements of roof

the maximum values of the 3 schemes are 82.9 mm

84.4 mm and 84.5 mm separately. A wide range tensile stress area appears with mining in roof; the maximum proportions of the tensile stress area occupying the roof area are 22%

22.3% and 23.5% separately. However

the time-varying laws of the tensile stress area show remarkable feature of imbalance and mutability. According to the process response laws of the stope structure under mining

the evaluating indices of the tensile stress damage area and the subsidence displacements of the roof are chosen. The optimal scheme is proposed and it is the scheme 1