为解决多次采动影响下大跨度煤巷支护难的问题,以高家梁矿20108工作面回风巷道为例,通过分析工程地质条件和工程岩体特性可知,20108回风巷道属于应力扩容膨胀型复合地质软岩,确定力学破坏机制为IABcⅡBDⅢDA复合型变形力学机制,提出采用锚网索带注耦合支护方案。基于FLAC如数值软件,对锚网索带注耦合支护方案进行数值计算,计算结果显示,与无耦合支护对比,屈服区域显著缩小,顶底板和两帮变形都得到有效控制。现场监测煤巷围岩变形表明,多次采动影响下煤巷两帮变形速率大于顶底板,表明两帮变形速率控制着20108回风巷道的使用功能。研究结果表明,锚网索带注耦合支护在采动影响下大跨度煤巷支护中取得良好的支护效果,数值计算表明,采动影响下大跨度煤巷采用耦合支护技术是可行的;现场监测结果也验证耦合支护技术的有效性和可靠性。
In order to solve difficult support problems of the large-span coal roadway under the second or multiple mining influence, an example of the working face 20108 ventilation roadway in Gaojialiang Coal Mine is presented. Through analyzing the engineering geological conditions and engineering rocks body characteristics, it is known that the roadway 20108 is the stress dilatancy expansion type composite geological soft rock. The damage mechanisms of roadway are the composite deformation mechanisms IABclIBDIIIDA; and then the bolt-mesh-cable-grout with steel band coupling support design is put forward. By using the large finite difference program FLAC3D, numerical analysis of coupling support design is conducted. The numerical results show that comparing with non-coupling support, the plastic failure zone is obviously reduced and floor deformation is larger than roof deformation of coal roadway. The deformation of roof; and the floor and two working slopes are effectively in control. The field monitoring deformation of roadway surrounding rock shows that, deformation rates of roadway two Working slopes under multiple mining influence are larger than those of the roof and floor, which indicates that deformations of two working slopes control the utilization function of ventilation roadway 20108. The results reveal that support effect of bolt-mesh-cable-grout with steel band coupling support is verygood in large-span roadway under mining dynamic loads. Based on the theory of numerical calculation, the application of coupling support to large-span coal roadway under multiple mining influence is feasible; and the field monitoring result also verifies the validity and reliability of coupling support proposed.