复合硬厚顶板采场覆岩垮落控制研究

Study on control of overburden collapse of composite hard and thick roof stope

针对西部弱胶结地区采场硬厚顶板来压步距大,易引起剧烈矿压显现的问题,提出对硬厚顶板注水软化的处理方案,使顶板冒落步距大幅缩短,矿压显现显著降低。以泊江海子煤矿113100工作面为背景,利用Fl AC3D软件,数值模拟现场施工过程,对比分析理论计算来压步距及有无注水软化孔工作面回采过程中应力场、塑性区演变情况,得出水力软化顶板破断的最佳步距;将钻孔注水软化顶板的施工方案运用于113100工作面的回采中,使直接顶的初次来压步距控制在20 m左右,基本顶的初次来压步距控制在30 m左右。结果表明:通过提前对覆岩顶板钻孔注水软化,可有效控制顶板初次垮落步距,实现顶板在预定位置垮落的目的,从而将工作面的顶板瞬时动力显现效应降到最低,保证工作面的安全回采。

Aiming at the problem that the large pressure step distance of hard thick roof in weakly consolidated area in western China was easy to cause severe ore pressure, the treatment scheme of water injection softening hard thick roof was put forward, so that the roof caving step distance was greatly shortened and the ore pressure appears significantly reduced.With No.113100 Face as the background, Flac3D software was used to simulate the field construction process, and the evolution of stress field and plastic zone in the stoping process of working face with or without water injection softening hole was compared and analyzed, and the optimal step distance of hydraulic softening roof was obtained. The construction scheme of drilling water injection to soften the roof was applied to the mining of No.113100 Face, so that the first pressing step of the direct roof was controlled at about 20m, and the first pressing step of the old roof was controlled at about 30m.The results showed that the initial caving step of the roof can be effectively controlled by water injection to soften the overlying roof in advance, so as to realize the purpose of caving in the predetermined position of the roof, minimize the instantaneous dynamic effect of the roof of the working face and ensure the safe mining of the working face.