沿空大断面巷道预应力锚注支护技术应用

Application of Pre-stressed Anchor Grouting Support Technology in Large Cross Section Roadways Along Goaf

针对沿空大断面巷道掘进期间围岩变形控制难题,以王家岭矿东翼胶带大巷为工程实例,应用预应力锚注裂隙岩体加固原理,采用预应力注浆锚杆与自应力注浆联合支护方式,选用快硬早强高流态微纳米硅质复合注浆料,改善煤岩体的整体性和约束应力状态,浆液的黏结作用使锚杆变为全长锚固状态,使锚杆、浆液结石体、围岩三者形成完整的整体,提高围岩抗剪强度、破碎煤岩体应力状态和煤岩体自有强度,支护7 d后围岩变形速度明显降低,顶底板、两帮最大移近量分别为179 mm、294 mm,比支护设计优化前分别少移近198mm、386mm。

In view of the difficult problem of controlling the deformation of surrounding rock during the excavation of large cross section roadways along goaf,taking the east wing belt main roadway of Wangjialing Mine as an engineering example,the principle of pre-stressed anchor grouting for fractured rock mass reinforcement is applied,and a combined support way of pre-stressed grouting anchor rod and self stress grouting is adopted.Fast hardening,early strength,and high flow regime micro-nanometer siliceous composite grouting material is selected to improve the integrity and constraint stress state of coal and rock mass.The bonding action of the serous makes the anchor rod into a full length anchoring state,integrate the anchor rod,serous stone body,and surrounding rock into a complete whole,improving the shear strength of the surrounding rock,the stress state of the fractured coal and rock mass,and the inherent strength of the coal and rock mass.After 7 days of support,the deformation speed of the surrounding rock is significantly reduced,and the maximum displacement amount of the top,floor,and two sides are 179 mm and 294 mm,respectively,compared to before the optimization of the support design,the displacement is reduced by 198 mm and 386 mm,respectively.