深部沿空巷道围岩主应力差演化规律与控制

针对千米深井沿空巷道围岩控制难题，以邢东矿2122运输巷为研究对象，采用FLAC3D模拟埋深550～1 250 m时巷道围岩主应力差与塑性区响应特征以及两帮主应力差演化规律。结果表明：① 沿空巷道顶板与实体煤帮主应力差由浅到深均呈先增高后降低至趋稳的趋势，煤柱帮主应力差呈山峰型对称分布；② 在埋深增加过程中，沿空巷道顶板和实体煤帮浅部主应力差敏感性度较小，进入中深部后变化较大；③ 随着埋深增加，两帮剪切、拉伸破坏区逐渐呈扇形分布并向深部扩展，且采空侧范围略大于巷道侧；④ 深部高应力和煤柱帮被主应力差长时间破坏使得实体煤帮主应力差峰值明显高于煤柱帮。基于此提出采用高预应力、强力支护系统进行深部沿空巷道围岩控制，并结合数值模拟研究结果确定了关键参数，现场实践表明，支护效果良好，实现了深部5 m宽煤柱沿空巷道围岩的有效控制。

Surrounding rock principal stress difference evolution law and control of gob-side entry driving in deep mine

In terms of the surrounding rock control problems in kilometer depth gob-side entry driving,the No.2122 haulage roadway in Xing-dong coal mine is investigated.The principal stress difference and plastic zone are studied in the process of buried depth from 550 m to 1 250 m with FLAC3D.Analysis result shows that:① the principal stress differences of roof and integrated coal beside the roadway firstly increase and then decrease,finally tend to be stable from shallow part to deep one,while one of coal pillar displays a symmetrical distribution shape of mountain peak;② the principal stress differences of roof and integrated coal beside the roadway in the shallow parts have less sensibility than that at the middle and deep parts with the increase of buried depth;③ the tension shear failure zones display a sector and expands to the depth,the area of which in the gob-side is a little bigger than that around roadway;④ the principal stress difference peak value in the integrated coal is obviously higher than the one in the coal pillar due to high stress in the depth and failed pillar by the principal stress difference in a long time.Based on above analysis,a high pre-tension and powerful supporting system are proposed to control the deep roadway of gob-side entry driving.Combined with the result of numerical simulation to determine key parameters,the field practice shows the supporting system proposed have achieved an effective control of surrounding rock at gob-side entry driving in deep mining with 5 m width coal pillar.