倾斜煤层开采离层空间发育特征的数值分析

Numerical simulation of the space growth of bed separations of overburden of inclined coal strata

为了获得倾斜煤层采动覆岩移动及离层空间分布特征,考虑覆岩的碎胀性,根据抗弯刚度的不同在相应的界面设置接触单元,应用数值模拟手段,获得了不同倾角的倾斜煤层开采上覆岩层破坏、移动与变形及离层的发展与分布的时空规律。研究表明:垮落带、导水裂缝带范围的最终形态呈上大下小的抛物线拱形形态,倾角越大,差值越大。采空区上方的离层空间的最大离层差值偏向于采空区的右上方,上下位岩层除了竖向离层外,还会产生水平错动。由于抗弯刚度的差异,二、三离层的体积比较小,第四离层位置的离层空间体积最大,且第四离层距离煤层140 m左右,认为是可充填的离层空间。

In order to obtain the movement of mining overburden and space distribution of bed separation of inclined coal strata, the location of the strata contact face inside the overburden was obtained by the difference of bending rigidity of strata and the contact face was simulated with the laminar layer contact element after considering the characteristics of the expansion of fractured rockmass. The space-time laws for the rupture, failure and movement of mining overburden, as well as the development and distribution of bed-separations were explored by numerical simulation. It is shown that the final shape of water flowing fractured zone, which is bigger in upper location and smaller in lower location, is a parabolas-arch. The bigger the inclined angle is, the larger the difference is. The upper and lower rock layers have the vertical and horizontal displacement. The difference of the biggest space of bed-separation is located in upward to the right. The size of the fourth separating space is larger than those of the second and the third separating spaces due to the differ- ence of bending rigidity. The distance of the fourth separating space to the coal seam roof is about 140 m. The fourth separating layer is regarded as the space allowed to be filled.