煤矿巷道锚杆支护应用实例分析

CASE STUDIES OF ROCK BOLTING IN COAL MINE ROADWAYS

在分析锚杆支护作用机制的基础上,提出高预应力、强力支护理论,强调锚杆预应力及其扩散的决定性作用;指出对于复杂困难巷道,应尽量实现一次支护就能有效控制围岩变形与破坏;介绍煤矿开发出的锚杆支护成套技术,包括巷道围岩地质力学测试技术、动态信息锚杆支护设计方法、高强度锚杆与锚索支护材料、支护工程质量检测与矿压监测技术,以及锚固与注浆联合加固技术;在分析煤矿巷道类型与特点的基础上,介绍高预应力、强力锚杆支护理论与技术的典型应用实例,包括千米深井巷道、软岩巷道、强烈动压影响巷道、大断面开切眼、深部沿空掘巷与留巷、采空区内留巷及松软破碎硐室加固。基于这些复杂困难巷道的特点与地质力学测试结果,进行巷道支护设计,通过矿压监测数据分析与信息反馈,评价支护设计的合理性与围岩稳定性。实践表明,采用高预应力、强力锚杆支护系统,必要时配合注浆加固,能够有效控制巷道围岩的强烈变形,并取得良好的支护效果。

Based on analyzing bolting mechanism,the theories of high prestress and intensive bolting are put forward,which emphasize the decisive part of the bolt prestress and its diffusion.It is pointed out that the primary supporting should be able to control the displacement and damage of the surrounding rock as soon as possible under complicated conditions.The complete bolting techniques for coal mine roadways are introduced,including geomechanics testing,the dynamic information method for bolting design,the materials of high strength bolts and cables,the construction quality detecting and monitoring techniques,and the combination techniques of bolting and grouting.Typical cases are described on the basis of roadway types,including the roadway with buried depth more than 1 000 m,the entry in soft rock,the entry strongly affected by active mining activity,the large section open-off cut,the entry driven along next goaf with a thin pillar,the entries retained for next sublevel and in the goaf,and the damaged chamber with soft and broken surrounding rocks.On the basis of the features of the roadways and field testing results,the reinforcement designs are carried out;and the rationality of the designs and the stability of surrounding rock are evaluated through the analysis and feedback to field monitoring data.These practices point out that the high prestress and intensive bolting system,combined with grouting if necessary,can effectively control the violent displacements of the surrounding rock and good reinforcement effects can be achieved.