综放回采工作面临空掘巷围岩破坏规律及控制研究

Surrounding rock failure law and control of gob-side entry driving in fully mechanized top coal caving face

以晋能控股王家岭煤矿20104工作面为工程背景,通过现场矿压监测、精细化数值模拟、力学机理分析和现场工业性试验相结合的方法,对临空掘进的20102回风平巷进行了研究。结果表明:20102回风平巷围岩变形破坏过程可分为初期缓慢增长阶段、快速持续增长阶段和加速增长阶段三个阶段;精细化数值模拟关于巷道两帮煤体中的支承应力变化规律证实了现场矿压监测结果的准确性,同时还指出对顶板岩层预裂后能够显著降低临空巷道围岩两帮煤体中的支承应力,从而减少巷道围岩破坏程度和收敛量;现场对顶板岩层进行高压水力预裂后,围岩顶底板和两帮累计收敛量分别减少了506mm和326mm,围岩变形量得到了一定程度的控制。研究成果为具有类似工程地质条件下临空掘巷提供了指导和借鉴意义。

Taking the 20104 working face of Wangjialing Coal Mine as the engineering background, through the combination of on-site ground pressure monitoring, refined numerical simulation, mechanical mechanism analysis and on-site industrial test, the 20102 return airway driven at gob-side was studied. The results showed that the deformation and failure process of surrounding rock in 20102 return airway can be divided into three stages: initial slow growth stage, rapid continuous growth stage and accelerated growth stage;the fine numerical simulation on the variation law of the supporting stress in the two sides of the roadway confirmed the accuracy of the on-site ground pressure monitoring results. At the same time, it was also pointed out that the pre-splitting of the roof rock can significantly reduce the supporting stress in the two sides of the surrounding rock of the empty roadway, so as to reduce the damage degree and convergence of the surrounding rock. After the high-pressure hydraulic presplitting of the roof and rock stratum on site, the cumulative roof-to-floor convergence and side wall convergence were 506 mm and 326 mm smaller, respectively, and the deformation of the surrounding rock was controlled to a certain extent.