摘要
水力压裂技术已经广泛在煤矿应用于处理工作面坚硬顶板问题,但其卸压机理并不十分明确。采用ELFEN数值模拟方法研究工作面坚硬顶板水力压裂处理对采动应力的影响,探讨卸压机理。数值模拟结果显示:对工作面顶板的水力压裂处理,主要是弱化顶板的完整性,使其在工作面推进后能够及时垮落,这种局部垮落,虽然不会显著影响支承压力分布特征,但局部直接顶的及时垮落会引起上覆基本顶和关键层的及时断裂和垮塌,影响采场覆岩大结构,进而影响支承压力分布特征。对工作面顶板进行持续压裂,可以降低初次垮落步距及平均来压步距。
Hydraulic fracturing has been extensively used for solving issues caused by strong rock layers above longwall coal panel.The related mechanism of mining-induced stress relief is not well understood.In this paper,a numerical study is performed using the hybrid finite/discrete element code ELFEN to investigate the effect of strong roof layers on mining-induced stress.It is found that hydraulic fracturing can reduce the integrity of the strong rock layers so that they can collapse timely as the longwall face moves ahead.The collapse of localized immediate roof may not substantially affect front abutment pressures.Continuous collapse of the immediate roof can cause timely fracture and collapse of the overlying main roof layers,affecting the large structure of the overburden in the stope,and thus affecting the distribution of mining-induced stress.Continuous hydraulic fracturing of the rock layers above longwall panel can reduce the distance of initial roof collapse and the distance of periodic collapse.
作者
高富强
GAO Fuqiang(State Key Laboratory of Coal Mining and Clean Utilization(China Coal Research Institute),Beijing 100013,China;CCTEG Coal Mining Research Institute,Beijing 100013,China)
出处
《采矿与岩层控制工程学报》
北大核心
2021年第2期1-9,共9页
Journal of Mining and Strata Control Engineering
基金
国家自然科学基金资助项目(51774185)。
关键词
水力压裂
采动应力
数值模拟
卸压机理
hydraulic fracturing
mining-induced stress
numerical simulation
stress relief mechanism
作者简介
高富强(1981-),男,河南扶沟人,副研究员,博士。E-mail:gaofuqiang@tdkcsj.com。
