不同采动对含断层底板破坏影响数值模拟

Numerical Simulation about the Different Mining Effects on the Failure of Floor with Fault

为了掌握不同开采方式对含断层底板岩体破坏规律的影响,确保承压水上安全开采,以实际工程为背景,基于FLAC3D软件构建了含断层底板岩体采动数值模型,针对上下盘开采顺序和工作面推进方向共4种方案进行模拟分析。研究结果表明,随着工作面推进,断层对周围岩体影响逐渐增大,致使塑性区与断层导通,且其内部出现明显的应力集中现象;当工作面推进方向和顺序相同,先开采下盘后开采上盘,其采动应力对底板塑性区破坏范围和深度较先开采上盘后开采下盘时大;当上下盘开采顺序一定,背向断层推进比对向断层推进时的底板岩体破坏程度和垂直应力分布更显著。因此,采用先开采上盘后开采下盘对向断层推进的方式更能减少对底板岩体的破坏,确保承压水上安全开采。

In order to master the effects of different mining methods on the rock failure law of floor with fault, and to ensure the safe mining upon confined water, a series of numerical models of rock mining on floor with fault based on FLAC3D software was constructed by taking practical engineering as the background. Aimed at mining order of hanging wall and footwall, as well as the advancing direction of working face, four kinds of mining methods were simulated and analyzed. The research results were concluded as follows. Firstly, with the advance of the working face, the influence of the fault on the surrounding rock mass gradually increased, which led to the conduction of the failure zone and the fault, as well as the appearance of obvious stress concentration inside. Secondly, when the advancing orders and directions of the working face were the same, compared with first mining of the hanging wall, the effect of the mining stress caused by exploiting the footwall firstly on the damage range and depth of the floor was relatively larger. Thirdly, when the mining order of hanging wall and footwall was fixed, the floor failure and the vertical stress distribution of back-to-back mining were more significant than that of face-to-face mining. There-fore, it was found that the face-to-face mining method with mining order from footwall to hanging wall could reduce the failure of the rock mass and ensure the safe mining upon the confined water.