巷内预充填无煤柱开采围岩应力分布及变形破坏特征

Stress Distribution and Deformation and Failure Characteristics of Surrounding Rock in Roadway Pre-filled Mining Without Coal Pillar

巷内预充填无煤柱掘巷技术可有效解决留窄煤柱沿空掘巷存在煤炭资源浪费的问题,阐述了该无煤柱开采方法的原理,采用数值模拟综合分析了巷内预充填无煤柱掘巷"二次掘采"过程中围岩的应力分布及变形破坏特征,总结了充填体在"二次掘采"过程中的作用机理。结果表明:在"二次掘采"过程中充填体受力状态较复杂,且始终处于高应力状态;本工作面回采阶段应力峰值向实体煤侧转移;沿空巷道顶板在靠近充填体上部的顶煤发生压剪破坏切落下沉,巷道浅部的顶板发生拉伸破坏,同时顶板层间发生剪切错动离层,实体煤帮在高应力作用下发生压剪破坏。

Pre-backfill without coal pillar technology in roadway can effectively solve the waste of resources in the roadway cutting along goaf with thin pillar. This article described the principle of mining method without coal pillar. The article also numerically simulates the stress distribution and distortion and failure characters of surrounding rocks during the ＂second mining＂when the new technology is used, and summarizes the mechanism of backfill during the＂second mining＂. Results show that the filling body has complex stress situation and maintains high stress during the whole process of the ＂second mining＂. Meanwhile, the stress peak of this working face is transferred to the solid coal side. In the roof of gob-side entry, top coal that near the narrow pillars drops because of compression and shear failures. At the same time, shear dislocation layer occurs between the roof layers; the coal sides experience compression and shear failures.