基于基本顶断裂位置的综放窄煤柱煤巷非对称支护技术研究

An asymmetric support technique for fully-mechanized coal roadway nearby narrow pillar based on the fracture position analysis in basic roof

针对王家岭煤矿20103综放窄煤柱煤巷顶板支护过程中出现的非对称大变形控制难题，采用钻孔窥视法对基本顶断裂位置和顶板双向移动特征进行现场实测，结合顶板煤体微裂隙非对称演化过程的CT识别，提出槽钢简式桁架锚索与单体锚索平行布置非对称支护技术，并对其组成结构和控制机制进行系统研究。得出：（1）距20103掘进工作面100--300m长度区间，基本顶在窄煤柱上方距巷道横截面铅垂中心轴2．918m位置断裂；（2）基本顶断裂后回转下沉引起巷道顶板发生两次离层和水平错动：一次离层和水平错动导致煤柱侧顶板沿巷道长度方向区域性断裂，二次离层和水平错动诱发煤柱侧顶板局部冒漏；（3）窄煤柱煤巷顶板煤体微裂隙演化过程具有明显的不对称性：水平错动带煤体微裂隙数量、发育速度和贯通速度大于扰动稳定带煤体微裂隙数量、发育速度和贯通速度；（41槽钢简式桁架锚索和单体锚索平行布置非对称支护机制：重点突出、刚柔并济、点线结合、均衡承载。20103窄煤柱煤巷采用槽钢简式桁架锚索和单体锚索平行布置非对称支护技术，煤柱侧顶板和回采侧顶板变形协调一致，围岩控制效果良好，研究成果对类似工程条件的巷道支护具有一定的理论意义和实用价值。

The support for the fully-mechanized coal roadway nearby narrow pillar in the mining face 20103 of the Wangjialing coal mine suffered large asymmetric deformation. In order to solve this problem, a technique was proposed. In the first step, the fracture position of the basic roof and two-way movement behavior was investigated using the method of borehole observation, then combing the CT scan technology for the asymmetric evolution process of coal roof microcracks, an asymmetric support technology using both parallel-arranged composed of channel steel truss cable and single cable was designed. Its composition structure and controlling mechanism were then researched in detail. The following results were obtained： （1） Away from the tunneling face 20103 100 - 300 m, fracture took place at the top of the narrow pillar, apart from the central plane of the roadway 2.918 m： （2） Roof delamination and horizontal dislocation have occurred twice in coal roof caused by the rotation and descending of basic roof. the first delamination led to a regional scale faults in the roof near the pillar side and parallel to the entry direction： the second delamination led to some site scale roof falls near the pillar side （3） Microcracks development on either side of the entry roof were asymmetric： the amount, developing speed and faults formation interval were discrepant between the horizontal dislocation zone and the stable zone; （4） The feature of the asymmetric support method using parallel-arranged composed of channel steel truss cable and single cable include： weak sites extra-strengthened, tuned by weaker support at relative strong sites, line shape supports accompanied by point supports, and the load on every supports were balanced. This method has been successfully implemented in the working face 20103, deformation on the roof at pillar side and coal rib side were adjusted to synchronous, the host rock was very effectively controlled. The result and experience are very useful to similar engineering conditions theoretically and practically.