采动影响对陷落柱活化导水机理数值模拟研究

Numerical Simulation of Mining Effect on Collapse Column Activated Water Conducting Mechanism

为研究采矿对陷落柱活化作用,利用数值计算软件FLAC3D对强充水陷落柱、不充水陷落柱和煤层底板中赋存陷落柱的破坏过程进行模拟,分析陷落柱及其周边围岩的应力、应变和塑性区的变化.研究表明,陷落柱在采动应力场和渗流场的相互作用下,渗流压力引起陷落柱围岩产生应变,同时采掘工作形成的应变也同样会引起渗流系数的变化.随着承压水压力的增大,陷落柱泥化带、裂隙带和破碎带的宽度都相应增大.对底板中陷落柱突水进行模拟,采动影响先产生在底板进而影响陷落柱.减小回采空间可以减小顶底板以及围岩的变形、破断和移动,保证底板隔水岩层的隔水能力.

To study the effect of mining on the activation of collapse columns, the full water filling and non water filling collapse columns and the collapse column in coal floor were numerically simulated using the software FLAC3D so to analyze the change in stress, strain, and plastic area of collapse column and its surrounding rocks. The result shows that, in the interaction of mining pressure field and seepage field, the strain of the surrounding rock of the collapse column is caused by seepage pressure and the changes of seepage coefficient is caused by mining. With the increase of pressure of artesian water, the muddy zone and fractured zone of collapse column increase correspondingly. The simulation shows that the mining activity first affects the floor and then the collapse column. Therefore by reducing mining room, the deformation, breaking, and moving of the surrounding rock, roof, and floor can be reduced so that the water-insulating capability of aquifuge of the floor can be ensured.