论文部分内容阅读
采动影响下完整底板防治水的重点是研究岩层由隔水层到导水通道的演化过程。煤层开采引起底板岩体承受压–拉–压循环荷载,并导致弹性模量变化。以弹性模量为损伤变量,采用双标量型D-P弹塑性损伤本构模型,根据成庄矿条件建立数值模型,分析采动底板导水通道演化规律。结果表明,(1)上一计算步煤壁处底板压缩破坏深度随顶板悬露面积增大而再次加深,工作面煤壁位置处底板压缩损伤深度的增长速率在充填体影响下迅速减小(顶板初次垮落),并最终达到稳定(顶板周期垮落);(2)采动底板中同时存在压、拉损伤破裂带,二者相互连通,决定了导水通道的位置;(3)充填体的弹性模量对底板破坏深度有很大影响,其值过低会导致破坏深度持续快速增加。由注水试验所得监测结果与数值模拟成果基本吻合。
Under the influence of mining, the key to preventing and controlling water of the complete floor is to study the evolution process of rock strata from aquitard to aqueduct. Coal seam mining causes the bottom rock mass to bear the pressure-tension-compression cyclic load and cause the elastic modulus to change. Taking the elastic modulus as the damage variable, a double-scalar D-P elastic-plastic damage constitutive model was adopted. According to the conditions of Chengzhuang Mine, a numerical model was established to analyze the evolution law of hydraulic conductivity channel of mining floor. The results show that: (1) The compressive failure depth of floor in the previous step is further deepened with the increase of the exposed area of the roof, and the growth rate of compression damage depth at the coal wall of the working face rapidly decreases under the influence of the filling body The roof collapses for the first time), and finally reaches a steady state (roof period caving); (2) the simultaneous existence of compressive and tensile rupture zones in the mining floor, which are interconnected and determine the position of the water guiding channel; (3) Body elastic modulus has a great impact on the depth of the destruction of the floor, the value is too low will lead to a sustained and rapid growth of damage depth. The results obtained from the water injection test are in good agreement with the numerical simulation results.