基于锚杆轴力实测的综采工作面区段煤柱稳定性分析

摘要

为了保障采掘工作的正常接续,实现矿井的高产高效,我国西部矿区综采工作面的区段平巷大多采用双巷掘进方式,巷间区段煤柱先后经历掘进,一次回采及二次回采的扰动影响,矿压显现剧烈.采用锚杆无损检测技术对区段煤柱采动影响区域进行了锚杆轴力实测,进而对区段煤柱锚杆支护体的实时支护状态及其稳定性进行评价,并对区段煤柱超前加固支护设计提出合理建议.研究结果表明,在工作面两端区段平巷里,随测试锚杆距工作面距离增大,锚杆轴力呈先增加至峰值后逐渐减小,直至趋于稳定的总体变化规律;锚杆轴力峰值位置正好对应着区段平巷围岩大量破坏与未破坏的交界区域;通过锚杆轴力变化可以较好地反映工作面前后方的采动影响剧烈范围,为工作面区段平巷超前支护范围及其预防加固措施提供参考依据.%In the mining area of western China,double entries are mostly excavated simultaneously at one end of a fully mechanized working face in order to keep the normal continuance of mining and excavation and realize a high production and efficiency of coal mine.Mine pressure appears very serious at the section coal pillars between two entries after they are disturbed by the excavation,two times of mining.Nondestructive tests of axial loads of bolts in coal pillars were performed at the severe mining influence areas of section lanes before and after the working face using a nondestructive testing technique.The real time bolt supporting state of section coal pillars and its stability evaluation were analyzed based on the test results.At the same time,reasonable suggestions were put forward for the forepole reinforcement measures of coal pillars.The research results show that the axial bolt load increases to peak and then decreases,until stable in an overall change trend in the entries when the distance if testing bolts is far from the working face.The peak axial bolt load is located exactly at the border area of severe destruction and undamaged area of section coal pillars.Severe mining influence scope before and after the working face can be better reflected by the changes of axial bolt loads,which provide a good reference for the forepole support scope of section entries and its prevention and reinforcement measures.