基于固体充填开采的井筒保护煤柱留设方法研究

Study on protective coal pillar left design method of mine shaft based on solid backfill mining

为解决固体充填开采工业广场煤柱时井筒保护煤柱的合理留设问题,根据井筒破坏特性,对充实率、井筒保护煤柱尺寸等充填开采条件下影响井筒失效主控因素进行分析,提出了基于充实率控制的井筒保护煤柱留设原理;以此为基础,分析了垂直剖面法、科瓦尔契克概率积分法及ABAQUS数值模拟法等井筒保护煤柱留设方法,并提出了剖面法设置煤柱边界,理论计算与数值模拟相结合逐渐缩小边界的充填开采井筒保护煤柱综合留设方法及设计流程,并将此方法应用于百善煤矿充填开采回收工业广场煤柱,得到不同充实率条件下井筒保护煤柱范围划分。结果表明,固体充填开采充实率控制在80%以上,以留设半径154 m井筒煤柱计算,至少可安全解放出煤炭174.5万t。

In order to solve a rational left problem of the protective coal pillar in the mine shaft when a solid backfill mining was applied torecover the coal pillars under the surface industrial park,according to the failure features of the mine shaft,an analysis was conducted onthe main factors affected to the mine shaft failure under the condition of a compact rate,size of the protective coal pillars in the mine shaftand other backfill mining conditions. The protective coal pillar left principle of the mine shaft was provided based on the compact rate con-trol. Based on the circumstances,an analysis was conducted on a vertical profile method,Kowarzik probability integral method,ABAQUSnumerical simulation method and other protective coal pillar left method of the mine shaft. A comprehensive left method and design processof the protective coal pillar in the backfill mining shaft was established with profile method to set up the coal pillar boundary and the theo-retical calculation and numerical simulation combined to steadily reduce the boundary. This method was applied to the backfill mining andrecovery of the coal pillar project under the industrial park of Baishan Mine and the protective coal pillar division of the mine shaft underthe different compact rate condition was obtained. The results showed that the compact rate of the solid backfill mining could be controlledover 80%. Based on a coal pillar calculation of the mine shaft with a left radius of 154 m,the coal under the industrial park at less couldbe safely released with a coal resource of 1. 745 million.