深部高应力软岩巷道变形特征及支护技术研究

以贵州土城煤矿141713运输巷为工程背景,针对该矿运输巷深部高应力软岩难支护问题,通过现场调研该巷道破坏特征、实验室用多功能粉末X射线衍射仪分析围岩成分,分析总结该巷道破坏机理,得出围岩强度低、黏土矿物占比大、支护方式不合理、采动影响、高应力和围岩渗水是该巷道变形破坏的主要原因。针对巷道破坏特征和机理提出“锚杆/索+钢筋网+注浆+U型钢棚”联合支护方案,并通过理论分析、数值模拟分析和现场实测验证。通过数值模拟支护后,巷道顶板最大下沉量和巷道最大底鼓量分别从160mm和60mm减小至45mm和40mm|巷道两帮最大移进量从60mm减小至14mm|最大主应力由24MPa增加到28MPa。现场监测结果表明,支护后巷道断面最大收敛率为9.87%,巷道围岩变形量在可控范围内,支护效果明显。

Study on the Failure Mechanism and Support of Deep High Stress Doft Rock Roadway

Abstract: In the engineering background of guizhou coal mine in sand-layered transportation lane 141713, about the mine transportation lane deep high stress soft rock supporting problem hard, roadway destruction features through the field investigation and laboratory with multi-function powder X-ray diffraction analysis of surrounding rock composition, the article analyses the failure mechanism of roadway, it is concluded that low intensity of surrounding rock and clay minerals content of the supporting way, unreasonable, mining effect, high stress, and the main causes of water seepage is the deformation of roadway surrounding rock. According to the characteristics and mechanism of roadway failure, the combined support scheme of "anchor cable + steel mesh + grouting + u-beam steel shed" was proposed, which was verified by theoretical analysis, numerical simulation analysis and field measurement. After numerical simulation support, the maximum subsidence of roadway roof and the maximum floor heave of roadway decreased from 160mm and 60mm to 45mm and 40mm respectively.The maximum movement of the two sides of the roadway decreased from 60mm to 14mm; The maximum principal stress increased from 24MPa to 28MPa. The field monitoring results show that the maximum convergence rate of roadway section after support is 9.87%, the deformation of roadway surrounding rock is under control, and the support effect is obvious Key words: High stress soft rock; Grouting; The roadway supporting; Numerical simulation; Monitoring