深井复合顶板煤巷变形机理及控制对策

针对深部高应力条件下复合型顶板煤巷的大变形问题，以江西曲江煤矿为例进行了现场调查、理论分析和工业试验等研究。首先，经现场调查发现该矿表现出了典型“三高”矿井的特点，加上顶板锚索和两帮锚杆无法充分发挥作用，使整个巷道支护系统失去平衡而发生破坏。然后，研究了深部高应力工作面煤巷的力学作用，认为该力学作用是一个渐进过程，其变形动力主要来自于巷道顶板压力，底板变形大是直接导致整个巷道系统失效的重要标志；另外，根据深部高应力复合型顶板煤巷的受力特征，建议应将顶板的控制作为关键部位，尽力维护顶板的完整性，提高岩层自承能力，使支护结构与围岩能够协调地工作，并提出了以“预应力桁架锚索”为主体，以“锚杆+锚索+钢筋网等支护”为辅助的综合控制技术。实践证明：经以“预应力桁架锚索”为主体的综合控制技术支护后的巷道，其变形较原支护有明显好转；监测数据表明：经91 d后，巷道两帮的相对收敛速率小于1.7 mm/d，而且顶底板的相对收敛量大大减少，最大值为297 mm，变形速度小于1.4 mm/d，处于稳定状态。

Deformation mechanism and control technology of coal roadway under deep well and compound roof

According to large deformation problems of compound-roof coal roadway under high stress,Qujiang Coal Mine in Jiangxi Province is taken as an example,and field survey,theoretical analysis and industrial test are performed.At first,the field survey shows that the mine has features of a typical three-high mine.Because the top anchors and side cables can be brought into full play,the whole supporting system of roadway loses balance and fails.Then,the mechanical function of the coal roadway is studied.It is concluded that the mechanical function is a gradual process,its deformation power comes from roof pressure,and the large deformation of floor is an important failure symbol.Moreover,on the basis of stress characteristics,it is suggested that the roof should be taken as the key supporting part,its integrity should be maintained,and the self-bearing ability of strata should be improved.The comprehensive control technology with the main body of prestress truss and anchor rope and the accessory body of cable + anchor + mesh reinforcement is proposed.Practice shows that the deformation of a supported roadway by means of the comprehensive control technology is markedly improved.The monitoring indicates that the relative convergence rate of sides is less than 1.7 mm/d after 91 days,and the relative convergence rate between roof and floor is greatly reduced,with the maximum value being 297 mm and the rate being less than 1.4 mm/d.So,the whole roadway is in stable status.