分层充填开采覆岩演化规律研究

Study on overburden rock evolution law of layered filling mining

为研究分层充填开采覆岩演化规律及对地表沉陷的影响,本文以邢台矿为例,采用数值模拟方法构建了采场宏观模型,分析了不同推进距离下分层充填开采覆岩应力及运移演化规律,并与单层充填开采进行对比。研究结果表明:①随着推进距离的增加,采充区域应力云图均呈现“X”弱应力区形态特征,分层充填开采的“X”弱应力区较同等条件下的单层充填开采面积更大,分层充填开采工作面前方应力集中峰值为21.149 MPa,相较同等条件的单层充填开采工作面前方应力集中峰值21.650 MPa要小,分层充填开采对矿压的改善效果优于单层充填开采;②随着工作面的不断推进,顶板沉降值均不断增大,顶板运移等值区域均呈现拱形形态,以沉降极值为中心呈现对称分布,随充填工作面的推进方向移动,分层充填开采顶板沉降极值为74.969 cm,小于同等条件下单层充填开采的顶板最大沉降值75.790 cm,分层充填开采对采充区域上覆岩层的控制效果更好,顶板活动相对更小,分层充填开采地表沉陷极值为60.23 cm,小于同等条件下单层充填开采地表沉陷极值60.83 cm,分层充填开采对地表沉降的开采扰动影响更小。

In order to study the evolution law of layered filling mining and its influence on surface subsidence,taking Xingtai Mine as an example,the numerical simulation method is used to construct the macroscopic model of stope,and the stress and migration evolution law of layered filling mining under different advancing distances are analyzed,and compared with the single-layer filling mining.The research results show that with the increase of advancing distance,the stress nephogram of mining and filling area shows the morphological characteristics of“X”weak stress area,and the“X”weak stress area of layered filling mining is larger than that of single-layer filling mining under the same conditions.The peak stress concentration in front of the layered filling mining is 21.149 MPa,which is smaller than the peak stress concentration in front of the single-layer filling mining under the same conditions of 21.650 MPa.The improvement effect of layered filling mining on mine pressure is better than that of single-layer filling mining.With the continuous advancement of the working face,the roof settlement values are increasing,and the roof migration equivalent areas are arched.The distribution is symmetrical centered on the settlement extremum,and moves with the advancing direction of the filling working face.The extreme value of roof settlement of layered filling mining is 74.969 cm,which is smaller than the maximum value of roof settlement of single-layer filling mining under the same conditions of 75.790 cm.The layered filling mining has a better control effect on the overlying strata in the mining and filling area,and the roof activity is relatively small.The extreme value of the surface subsidence of the layered filling mining is 60.23 cm,which is smaller than the extreme value of the surface subsidence of the single-layer filling mining under the same conditions of 60.83 cm.The layered filling mining has less influence on the mining disturbance of the surface subsidence.