卸压孔浅部填充技术应用与围岩控制效果分析

Application of shallow filling technology of pressure relief hole and analysis of surrounding rock control effect

大直径钻孔卸压是深部高地应力巷道防治冲击地压的常用措施。本文针对郭屯煤矿2303轨道顺槽围岩变形严重时仍需要采取大直径钻孔卸压防治冲击地压为工程背景,提出了浅部填充卸压孔以提高浅部围岩整体性的措施。首先根据弹性理论,建立填充圆孔力学模型,推导出填充圆孔周围围岩任一点的应力表达式,并确定填充材料应选用速凝高强材料;然后选择工程实验地点进行浅部卸压孔填充,并进行现场监测。结果表明,浅部填充后,靠近卸压孔位置的锚杆轴力要高于远离卸压孔位置的锚杆轴力,围岩变形量明显降低,说明卸压孔浅部填充技术能够在保证深部煤体卸压效率的同时提高浅部围岩的强度。

Large diameter borehole pressure relief is a common measure to prevent rock burst in deep high ground stress roadway.In this paper,aiming at the engineering background that large diameter borehole pressure relief is still needed to prevent rock burst when the surrounding rock deformation of 2303 track crossheading in Guotun Coal Mine is serious,the measures of filling pressure relief hole in shallow part to improve the integrity of shallow surrounding rock are put forward.Firstly,according to the elastic theory,the mechanical model of the filled circular hole is established,and the stress expression of any point of the surrounding rock around the filled circular hole is derived,and the quick-setting high-strength material should be selected as the filling material.Then select the engineering experiment site to fill the shallow pressure relief hole and carry out on-site monitoring.The results show that after shallow filling,the axial force of the bolt near the pressure relief hole is higher than that far away from the pressure relief hole,and the deformation of the surrounding rock is obviously reduced.It shows that the shallow filling technology of the pressure relief hole can improve the strength of the shallow surrounding rock while ensuring the pressure relief efficiency of the deep coal body.