特厚煤层小窑采空区充填复采技术研究与应用

Research on Filling Repeated Mining Technology in Small Pit Goaf in Extremely Thick Coal Seam and Its Application

为了保证包含小窑采空区的工作面实现正常推进、安全回采。采取先充后采充填复采技术,先用无机材料对小窑采空区进行注浆充填处理,根据工作面与小窑采空区位置关系在小窑采空区内部形成一个截割层和关键承载层,使其能够在工作面通过小窑采空区时维护回采工作面顶板和煤壁区围岩的稳定,然后布置正规综放工作面进行回采。根据复采过程中小窑采空区关键承载层力学结构,基于重物低速冲击板结构力学模型,采用机理分析与理论计算等方法对小窑采空区注浆充填机理、小窑充填区域承载关键层的稳定性进行系统分析,得出维护采面顶板和煤壁区围岩稳定的关键承载层强度和厚度参数。采用分层注浆充填技术构筑一定厚度的关键承载层能够维护采面推过小窑采空区时顶板和煤壁区的稳定。

To ensure normal advance and safe mining of working face containing small pit goaf,the technology of filling with repeated mining is introduced in this paper,that is,the inorganic materials are used to fill the small pit goaf first,which can form a cutting layer or key bearing layer inner the small pit goaf according to the position relation between the working face and goaf,and makes that it can main-tain the stabilities of face roof and surrounding rock when the face passing through the small pit goaf.Then,the normal fully mechanized caving face is arranged for mining.In the paper,based on the me-chanics structure of key bearing layer in small pit goaf during the process of repeated mining,and the mechanics model of weight drop and low speed impingement plate structure,we conducted systematic analysis on the mechanism of grouting filling in small pit goaf and the stability of regenerated key strata in the filled area of small pit by using mechanism analysis and theoretical calculation,and figured out the intension and thickness parameters of key bearing layer for maintaining the stability of face roof and surrounding rock around coal wall.The results show that applying the technology of grouting filling in layers to build key bearing layers in a certain thickness can maintain the stability of roof and coal wall areas when the working face mining through the small pit goaf.