高地应力切顶留巷围岩快速控制技术研究

Rapid surrounding rock control of roof cutting roadway retaining under high ground stress

为解决深部高应力区切顶留巷围岩破碎、初期支护手段无法有效控制围岩的难题,以陈四楼煤矿十七采区21702工作面为实际工程背景开展切顶留巷围岩控制技术研究。根据工作面地质条件,分析切顶留巷的变形机理,设计切顶爆破参数及初期巷道的支护方案。针对工作面推进过程中,巷道变形大,围岩破碎等情况,设计切顶留巷补强支护方案:采用一种新型速凝、早强的无机双液注浆材料对切顶留巷破碎围岩注浆加固,快速有效地控制巷道变形;同时设计柔性挡矸自成墙体的巷帮挡矸措施,实现主、被动结合的切顶留巷补强支护方式。结果表明:在陈四楼煤矿21702工作面切顶留巷采取巷道补强技术,留巷巷道在二次采动应力作用下,顶板下沉量最大为147mm,两帮位移量最大为335mm,底板底鼓量最大为402mm,留巷围岩得到有效控制。

Aiming at the broken surrounding rock in roof cutting roadway retaining of deep high stress area is and the initial support can’t control the surrounding rock,the surrounding rock control for roof cutting roadway retaining is studied based on the engineering background of Chensilou Coal Mine. According to geological conditions of the working face, deformation mechanism of the retained roadway is analyzed, and the blasting parameters and initial roadway supporting scheme are determined. In view of the large roadway deformation and the broken surrounding rock during working face advancement,a reinforcing support scheme of the roadway is proposed,using a new quick setting and early strength inorganic double liquid grouting material to reinforce the broken surrounding rock,and quickly control the roadway deformation;at the same time,the gangue retaining measure is designed using the falling gangue to the form flexible gangue retaining wall,so as to combine active and passive reinforcement support for roof cutting roadway retaining. The practice in 21702 working face of Chensilou Coal Mine show that,the surrounding rock of the retained roadway was controlled under the secondary mining stress,the maximum roof subsidence was 147 mm,the maximum displacement of two sides was 335 mm,and the maximum floor heave was 402 mm.