平三矿庚组煤层顶板控制

ROOF CONTROL FOR SEAM-F AT MINE NO 3, PINGDINGSHAN

处于冒落带的老顶,当其厚度不大时可用强切的办法将其沿放顶线切断。为此,必须同时做到下列三点:①用采场支柱初撑力平衡工作空间上方冒落带岩重;②用切顶支柱初撑力平衡极限悬顶距时采空区上方老顶及其附加岩层的重量;③用采场支柱初撑力与切顶支柱初撑力所形成的反力矩平衡老顶岩梁由其重量所形成的力矩。通过对平顶山三矿庚组煤层顶板控制实测参数的验算,说明上述切断老顶的准则是正确的。

The medium thick main roof hanging over thegoaf may be forced to break along the breaking-off line. However, the following points must berealized at the same time: 1) the weight of rockabove the working space should be balanced by theinitial working resistance of the props of face; 2)the weight of the main roof and the idditionalstrata above the goaf with the overhanging roofbeing up to its limit span, should be balanced bythe initial working resistance of the breaker props;and 3) the moment induced by the weight of themain roof rock beam should be balanced by thecounter moment resulted from the initial workingresistance of the face props as well as the breakerprops. After having been checked with the practi- cal roof control parameters of the seam F at MineNo 3 of Pingdingshan mining district, the abovementioned criterion proved correct.