城郊矿深部工作面切顶留巷工程试验研究

Engineering experiment on gob-side entry retaining by roof cutting of deep mining face in Chengjiao coalmine

针对深部沿空留巷围岩变形剧烈、难支护的问题,基于切顶留巷技术原理,采用理论分析、数值模拟和工程试验相结合的方法,对深部切顶留巷可行性进行系统研究。通过聚能爆破切顶,可使基本顶关键块触矸点前移、触矸面积增大,提高采空区矸石支撑系统的刚度,从而缓解实体煤帮和巷旁支护体所受压力。根据深部切顶留巷围岩变形及应力分布特征,将沿空巷道划分为超前影响区、留巷变形区和留巷稳定区3个维控区域,基于区域特点,对各个区域进行详细的方案及关键参数设计。研究成果在城郊煤矿21304工作面进行现场试验,深部围岩变形得到有效控制,留巷各项指标良好,从而验证了深部切顶留巷的可行性及所设计方案的正确性。

In response to the problems of severe deformation and difficult support of deep gob-side entry retaining,based on relevant technical principles,the feasibility of deep gob-side entry retaining by cutting roof was studied systematically through theoretical analysis,numerical simulation,and engineering test.Cutting roof by cumulative blasting can move forward the touch point between key block and gangue,increase its contact area,enhance the rigidity of goaf gangue support system,and,thus ease the load of roadside support and buttock.According to the deformation characteristics and the stress distribution of the surrounding rock in deep gob-side entry retaining by cutting roof,the gob-side entry is divided into three control zones:advancing affected zone,deformation zone,and stable zone.Beyond that,detailed schemes and key parameters of each zone are designed based on the features of the zones.The research results have been used in working face 21304 of Chenjiao coalmine.The deformation of deep surrounding rock is controlled effectively and the indicators of remaining roadway are good,thus verifying the feasibility of deep gob-side entry retaining by cutting roof and the correctness of the design scheme.