Surrounding Rock Control Mechanism And Application Of Gob-side Entry Retaining By Cutting Roof In 11101 Gangue Filling Working Face Of Jingu Coal Mine

The roof cutting and goaf retaining technology based on the integration of"mining,filling,and retaining"is currently a hot topic and focus of continuous mining without coal pillars,and is also an important way to achieve green water,green mountains,and ecological environment protection in mining areas.However,some mines have difficulty controlling the deformation of the surrounding rock of the roadway after applying the technology of gangue filling along the goaf,which seriously affects the production of the mine.This article takes the 11101 gangue filling working face along the goaf as the engineering background,and analyzes the factors affecting the stability of the surrounding rock of the gangue filling working face along the goaf based on preliminary on-site research and literature search;FLAC^3D numerical simulation was used to study the improvement of stress in the surrounding rock of the goaf retaining roadway in the gangue filling working face due to top cutting pressure relief,and the optimal top cutting parameters were determined;Analyzed the characteristics of the deformation stage of the surrounding rock of the goaf retaining roadway filled with gangue,and proposed the control technology and plan for the surrounding rock of the goaf retaining roadway.The on-site application was good,and the following conclusions were obtained:（1）Based on the influencing factors of rock pressure behavior of solid filling and the theory of"size structure"of gob-side entry retention,the influencing factors of surrounding rock stability of gob-side entry retention in Jingu Coal Mine’s gangue filling working face were analyzed using FLAC^3D numerical simulation software.Due to the limited engineering geological conditions and filling process in Jingu Coal Mine,the filling rate is low and the deformation of surrounding rock cannot be effectively controlled.In response to this situation,a roof cutting and pressure relief technology is proposed to cut off the stress transfer during the roof collapse process in the goaf and maintain the stability of surrounding rock.Through numerical simulation,the control effect of roof cutting and pressure relief technology on the stability of surrounding rock in the goaf retaining roadway is verified.（2）In order to determine the roof cutting parameters of the gangue filling and roof cutting along the goaf retaining roadway,based on theoretical analysis and numerical simulation,the optimal roof cutting plan for the 11101 transportation channel is obtained as follows:the top cutting height is 6m,the top cutting angle is 15°,the spacing between blast holes is 300mm,and the sealing length is 2m.In view of the phased characteristics of rock pressure behavior in the goaf retaining roadway with gangue filling and roof cutting,a mechanical model of surrounding rock at different stages is established,and the support modes at different stages of the retaining roadway are determined through stress analysis,providing a theoretical basis for the control of surrounding rock in the goaf retaining roadway with gangue filling and roof cutting.（3）According to the technological characteristics of retaining roadway along goaf with gangue filling and roof cutting,as well as the bearing characteristics of the gangue filling body on the roof,the principles and phased control techniques for surrounding rock control of the roadway along goaf with gangue filling working face are proposed.The basic support in the roadway,auxiliary support in the roadway,single pillar withdrawal plan,and grouting of the roadway side filling body are studied,and a comprehensive control technical system for surrounding rock in the roadway along goaf with gangue filling and roof cutting is established.（4）The research results of retaining roadway along goaf with gangue filling and roof cutting were applied industrially in 11101 working face of Jingu Coal Mine and achieved good results.Using the gangue filling and roof cutting pressure relief technology can effectively control the deformation of surrounding rock,solve the problem of difficult control of surrounding rock deformation during filling,improve the resource recovery rate of Jingu Mine,effectively solve the problems of gangue discharge,enterprise production expansion,mining and replacement,and create economic benefits of about 51876600 yuan.The thesis has 66 diagrams,10 tables,and 102 references.