大采高工作面回撤通道水力压裂卸压与矿压规律研究  

Study on hydraulic fracturing pressure relief and ore pressure law in retreat channel of large mining height working face

作　　者：王志超 WANG Zhichao(CCTEG Coal Mining Research Institute,Beijing 100013,China)

机构地区：[1]中煤科工开采研究院有限公司,北京100013

出　　处：《中国矿业》2024年第4期192-200,共9页China Mining Magazine

基　　金：中国煤炭科工集团科技创新创业资金专项面上项目资助(编号:2018MS021);中国煤炭科工集团有限公司科技创新创业资金专项项目资助(编号:2019-2-ZD005)。

摘　　要：工作面进入末采阶段时与回撤通道的距离逐渐缩短,煤柱逐渐进入塑性破坏状态。为探究回撤通道围岩灾变过程,计算了回撤通道后方保护煤柱的安全宽度,依托数值模拟方法研究了煤柱宽度渐变条件下垂直应力演化规律,分析了煤柱渐进破坏机理,并实施了水力压裂卸压治理技术。研究结果表明:回撤通道前方煤柱的垂直应力分布存在“马鞍”形-“平台”形-“陡峰”形的变换规律,可将采动应力的影响划分为稳定阶段、叠加阶段、突变阶段和转移阶段。以柠条塔煤矿为例,开展了水力压裂卸压技术,包括注水压力、钻孔间距、钻孔压裂段数等参数的计算和现场布置方案。工作面与回撤通道贯通期间的支架阻力最大平均值为4 278 kN,活柱下缩量与来压步距得到了有效控制,顶板下沉量为145~200 mm,两帮变形量为340~450 mm,表明水力压裂技术取得了良好的卸压效果。As a working face enters the final mining stage,the distance to the retreat channel gradually shortens,causing the coal pillars to enter a state of plastic deformation.To explore the rockburst process in the retreat channel,the safe width of the protective coal pillars behind the retreat channel are calculated.Using numerical simulation methods,the evolution of vertical stress under varying coal pillar width is studied,and the progressive failure mechanism of the coal pillars is analyzed.Additionally,hydraulic fracturing pressure relief technology is implemented.The results indicate that the vertical stress distribution in front of the retreat channel undergoes a transition from a“saddle-shaped”to a“plateau”to a“steep peak”pattern,and the influence of mining stress can be divided into stable,superimposed,sudden change,and transfer stages.Taking the Ningtiaota Coal Mine as an example,hydraulic fracturing pressure relief technology is applied,including the calculation of water injection pressure,borehole spacing,and the number of fracturing stages,along with on-site implementation.The maximum average support resistance during the passage of the working face through the retreat channel is 4 278 kN. The shrinkage under the live column and the compression step distance are effectively controlled. The roof subsides by 145-200 mm, and the deformation of both sides is 340-450 mm. These results indicate that hydraulic fracturing technology has effectively relieved pressure.

关 键 词：回撤通道 覆岩应力 水力压裂 矿山压力 切顶卸压 

分 类 号：TD323[矿业工程—矿井建设]