采场覆岩破坏流固耦合的数值模拟分析

Numerical Simulation of Liquid-Solid Coupling of Overburden Failure in Mining Stope

为了分析浅埋煤层中渗流场与应力场相互影响,在理论分析的基础上建立了厚松散层富含潜水浅埋煤层开采的数值模型.浅埋煤层开采过程中采场覆岩破坏的流固耦合模拟表明,渗流场与岩体应力场耦合对覆岩的破坏有很大影响.在基本顶岩层悬梁达到接近极限破断距时,岩层破坏受水压的扰动十分敏感,在渗流影响下很容易失稳;在上覆岩层发生整体破断时,岩层的渗透系数、潜水流量及潜水水头都将发生突变,这些渗流参数的突变进而影响上覆岩层的稳定性.

In order to analyze the mutual effect of water seepage field on stress field in shallow seam mining,the numerical simulation model is built under the condition of shallow coal seam covered with thick loose layer and ground water on the basis of theory studying.The liquid-solid coupling simulation in the rock of face in shallow seam mining indicates that the couple of seepage field and stress field has a significant effect on the failure of overburden.The failure of rock becomes very sensitive to the disturbance of hydraulic pressure when the distance of basic roof rock beam reaches the limit interval,makig the beam much easy to lose steady.When the overburden rock as a whole failures,all the parameters of permeability,ground water flow rate,and ground water head will have a sudden change,which in turn,affecting the stability of the overburden.