基于基本顶断裂位置的综放沿空掘巷煤帮支护技术

针对深部综放开采大断面沿空掘巷不易支护的难题,采用理论分析及现场实践的方法,研究了深部综放开采大断面沿空掘巷煤帮的破坏特点,揭示了帮部长锚索结合锚网联合支护的作用原理,提出了根据钻进煤粉量的变化来判断基本顶断裂线位置及确定深部沿空巷道巷帮锚索支护长度的方法,并在东滩矿1306工作面验证了该方法的有效性。研究表明:深部综放开采大断面沿空掘巷具有水平变形大,两帮鼓出大,特别是实体煤帮鼓出严重的特点;帮部长锚索结合锚网联合支护能够在浅部通过锚杆群和金属网形成点面结合的支护体系形成挤压加固墙,从而抵抗塑性区煤体对其侧向压力,起到加固巷道的作用;基于钻进煤粉量、围岩压力和顶板的断裂之间的联系,提出了深部综放开采大断面沿空掘巷实体煤帮的控制对策和深部沿空巷道实体煤侧巷帮锚索支护长度的确定方法;以东滩矿1306轨道巷为例进行了实体煤帮的钻孔煤粉测试,并基于测试结果进行了实体煤帮加固设计;现场工程实践表明加固后实体煤帮的水平变形明显减小,证实了该加固方法的有效性。

Solid coal rib support technology of fully-mechanized mining along gob-side entry driving based on main roof fracture location

In order to solve the difficulty of roadway support along gob in deep fully-mechanized caving mining,the theoretical analysis and field practice methods were used to study the damage characteristics of coal ribs along large-area roadways in deep fully-mechanized caving mining. Based on the working principle of the combined anchor-net support,and a method to determine the location of the fracture line of the main roof and the length of long anchor cable in the coal roadway along the deep gobwas put forward according to the variation of the amount of pulverized coal in the process of drilling,and the effectiveness of this method was verified in No.1306 working face of Dongtan Coal Mine. The research shows that the gob-side groove of the deep fully-mechanized caving has the characteristics of large horizontal deformation and large outburst of both coal sides,especially the serious outburst of solid coal side. The working principle of the combined support of anchor cable and anchor net is as follows: In the shallow part,the extrusion reinforcement wall is formed by the support system of point-to-surface combination of anchor cable group and metal anchor net,which resists the lateral pressure of coal body in the plastic zone and strengthens the roadway;The relationship between the amount of pulverized coal drilled,the pressure of surrounding rock and the fracture of roof was established.Based on this,the control countermeasures of solid coal side-wall along gob of deep fully mechanized enlarged cross-section and the determination method of bolt and cable support length of solid coal side-wall along gobwere put forward;Taking the No.1306 track trench of Dongtan Coal Mine as an example,the borehole pulverized coal test of the solid coal side along the gob trench of the fully-mechanized enlarged section was performed. On this basis,the reinforcement design of solid coal side is carried out.The results show that the horizontal deformation of the solid coal side decreases significantly after reinforcement,which confirms the effectiveness of this reinforcement method.