Study on Stability Control of Surrounding Rock Along Mine Seam Gateway with Loose and Swelling Soft Rock

In order to effectively contral the stability of the mining gateway in No.B13-2 seam of Shajihai Mine,a microscopic structure measurement and test,a com position analysis and an indoor physic mechanics experiment were conducted on the surrounding rock of the mining gateway.The results showed that a clay mineral Co ntent of the roof and floor were all high and were taken 43.2% and 65.7% of the total mineral content individually.The uniaxial compression strength of the glutinite,coal and mudstone was all low and the max strength of the mudstone was only 13.726 MPa.The water absorption ability of the mudstone was high and after the water absor ption,the strength of the mudstone would be highly reduced.Thus the soft rock type of the gateway determined was jointed-swell and the deformation mechanics mecha nism and conversion technology of the soft rock gateway were determined.A coupling support technology of a constant resistance high deformation bolt(anchor)+ steel mesh + floor angle bolt was provided and applied to the engineering practices.The site monitoring and measuring results showed that the deformation of the surroundin g rock was low,the max roof subsidence,the convergence of the two sidewalls and the floor heave value were 187 ,212 and 350 mm individually and the support effect w as excellent.The support countermeasures applied could effectively control the stability of the seam gateway with loose and swelling soft rocks in Shajihai Mine.