Overburden breaking characteristics and surrounding rock stability of withdrawal channel

SHI Jiabin; LIU Husheng; CUI Dongliang; JI Zhi; DUAN Wei

doi:10.11799/ce202311039

Abstract：In response to the shallow burial and high hardness of the coal body in Shangwan Coal Mine,when the working face enters the final mining area,it faces challenges such as strong mining pressure,intensified roof caving,and severe deformation of roadway surrounding rock.The geological conditions of the 12306 working face in Shangwan Coal Mine are taken as engineering background to study the impact of the roof fracture position on the stability of the coal pillar in the withdrawal channel during the process from entering the final mining area to the connection of the withdrawal channel.Theoretical analysis is carried out using numerical analysis and on-site measurement,the optimal breaking position of the final mining roof is studied,providing a theoretical basis for the research on the control technology of the final mining roof in the 12306 working face.The research results show that the optimal breaking position is located behind the support based on the mechanical models of the three basic breaking structures of the basic roof when the withdrawal channel is connected.Comparative numerical simulation research shows that when the breaking position is located behind the support,the surrounding rock stress and support load of the withdrawal channel are determined,the high stress areas of the coal pillar are all at the minimum value,and combining with the working face within the range of 50～0 m of the final mining on site,the roof is broken behind the support by adjusting the mining speed,thereby achieving a pressure relief effect.The on-site construction effect is favorable.