关键词: “三软”煤层 沿空掘巷 窄煤柱 锚网支护

Abstract: The technology of driving along the goaf can significantly improve the recovery rate,but in the area of stress concentration between the working face and adjacent goaf,the difficulty of roadway support is high,which leads to the application of the technology is limited.Aming at the problems of large deformation and higher repairation rate of "three soft" coal seam in Zhengzhou Mining Area,according to the limit equilibrium theory,this paper analyzes the stress state of the surrounding rock of the roadway,puts forward the corresponding bolt net support technology,and obtains the reasonable width of the small coal pillar of 2 m.At the same time,FLAC2D sotware is used to analyze the law of the inner supporting pressure of the coal pillar after the mining of 31071 and 31091 working faces,to explore the key factors that affect the deformation of the surrounding rock of the roadway,and to design the combined support scheme of the anchor mesh cable with the installation prestress of the anchor rod of 50 kN.The main parameters are as follows: the specification of the top anchor rod is 20 mm×2 400 mm,the spacing between the rows is 750 mm×800 mm;the specification of the side anchor rod is 20mm×2 000 mm,the spacing between the rows is 700 mm×800 mm.The industrial test was carried out on the air return roadway of 31091 working face.The experimental results show that the scheme has a good effect.

Key words: "Three soft" coal seam,Gobside entry driving,Narrow coal pillar,Bolt net support