Study On The Stability Of Narrow Coal Pillars And Surrounding Rock Control Of Roadway Driving Along Goaf In Baoxing Coal Mine

How to improve the recovery rate of coal mine while ensuring the stability of soft rock roadway during excavation and working face mining has always been a difficult problem in coal mining process.In this paper,the 11073 transportation lane of Boxing Coal Mine is taken as the research object.Based on the geological conditions of soft rock roadway,theoretical analysis,numerical simulation and on-site observation are used to study the stability of narrow coal pillars and the surrounding rock control problems along the roadway.Firstly,according to the surrounding rock failure characteristics of the 11073 transportation lane and the lateral pressure distribution of the upper section Goa,the roadway is reasonably arranged.Through the field investigation and coal physics and mechanics experiments to determine the mechanical parameters of the rock surrounding the roadway,combined with the relevant parameters using the parabolic strength criterion to calculate a reasonable narrow coal pillar width.Then according to the mechanistically characteristics of the surrounding rock of the 11073 transportation lane,the FLAC3 D numerical simulation software was used to establish the corresponding model to study the distribution of the lateral pressure of the upper Goa in the edge coal seam and the coal under different coal pillar width during the roadway excavation and working face mining.According to the theoretical analysis and simulation results,the reasonable coal pillar width of 3 m is established according to the deformation and failure of the column.Finally,the support scheme of 11073 transportation lane in Boxing Coal Mine is proposed.The FLAC 3D numerical simulation software is used to analyze the effect of different top anchor spacing on the stability of surrounding rock of the roadway.The optimal and reasonable spacing of the top anchor is determined,and combined with the actual situation on site.The support method of "bolt(cable)+ anchor net + U-shaped steel" is adopted.During the Hemingway excavation and the mining pressure during the mining period,the surrounding rock of the roadway has maintained good stability,which provides a certain reference value for the construction under similar geological conditions.