无底柱崩落采矿大断面结构参数的数值模拟研究

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

针对金山店铁矿亟需确定的大断面结构参数问题,采用东北大学研制的SLS崩落放矿模拟系统和ITASCA公司的岩土工程软件FLAC3D,对该矿三期的采场结构参数进行了模拟分析和研究。数值放矿试验表明,崩矿步距对矿石回收指标影响较大,崩矿步距3.5～4.5m更有利于指标回收,兼顾爆破参数因素时推荐为3.5m。通过进路群开挖的数值模拟,并对开挖过程围岩的位移、应力和塑性区进行分析,发现开挖后塑性区范围不大,巷道具有良好的稳定性。因此,拟采用的进路参数从矿石回收指标和巷道稳定性方面看是较合理的方案。

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 1TASCA 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.