Numerical simulation of structural parameters of large section pillarless sublevel caving of Jinshandian Ore Mine

Aiming at the problem of pillarless sublevel caving structural parameters of the third period mining area of Jinshandian Ore Mine,the possible structural parameters are simulated and analyzed by using sublevel caving simulation system –SLS which is developed by Northeastern University of China and the geotechnical engineer software-FLAC3D which is developed by ITASCA Inc.The numerical experiment indicates that independent advance of ore breaking influences the recovery index evidently,and the independent advance of ore breaking of 3.5-4.5 m has more advantage in recovery index.Also considering the rock blasting effect,the independent advance of ore breaking of 3.5 m is recommended.The numerical simulation of sequential excavation of tunnel groups in a mine block is also carried out.By analyzing the displacements,stresses and plastic zone of excavation simulation,it is concluded that the tunnel groups have satisfactory stability with the designed structural parameters.To sum up,sublevel height of 14 m,drift interval of 16 m,tunnel width of 3.6 m and tunnel height of 3.2 m are reasonable for both the recovery index and the surrounding rock stability.