长壁留煤柱支撑法开采顶板结构分析及应用

采用长壁留煤柱支撑法开采时会产生两个问题：一是煤柱尺寸留设过小，在限定的开采区域内会发生工作面切顶事故;二是煤柱尺寸留设过大，又会形成跨几个区域大面积顶板垮落事故.为了解决这两种顶板垮落问题，建立了＂连续梁＂力学模型，计算出不同位置、不同性质的煤柱受力状况，并运用RFPA2D软件对郭家湾煤矿采场围岩破坏进行了数值模拟，对顶板结构进行了分析，并得出两种问题顶板垮落的不同特征.据此，提出了设立关键点和关键区的监测方案，通过监测不同敏感区域的煤柱，来解决这两种顶板灾害问题.

Analysis of Roof Structure on Longwall Remaining Coal Pillars Support Mining and Its Application

In longwall remaining coal pillars support mining, if the coal pillars are very small in size, the roof cutting accident is likely to happen in a limited exploitation area; while if the coal pillars are very large in size, roof falling crossing the mining area is likely to happen. According to building mechanics model in order to solve these two kinds of roof falling, the continu- ous beam model is established to calculate the stressed state of coal pillars with different properties. Then the software RFPA^2D is used to numerically simulate the failure of surrounding rocks in mining area of Guojiawan coal mine. Meanwhile, the roof structure is analyzed, obtaining two different roof falling characteristics corresponding to the two problems. On the basis of this, we have proposed a scheme in which the coal pillars at some key points and in key area are monitored to solve the problem of two kinds of roof falling.