Stability Control Technology of Deep Mine Rock Roadway with Large Cross Section and Soft Broken Surrounding Rock

Based on the soft and broken surrounding rock conditions of the-1 100 m west roadway in depth of 1 300 m in Suncun Mine,in order to change the serio us strong condition of the mine strata pressure behaviors occurred during the mine roadway heading period and to reduce the rheologic speed of the surrounding rock a fter the mine roadway heading completed,the high strength yield bolt,enlarged bolt length,rational pre-tension made during the bolt installed and other measures were a pplied to effectively control of the surrounding rock deformation in the roadway. The fast high pre-tension and high strength new type anchor was applied to the seconda ry support. The slit wedge tubing bolt was applied to the advance support and the shotcreting and then bolt construction sequence of west roadway. The trial results sho wed that after 70 days of the mine roadway excavation and heading,the max subsidence of the roof was 65 mm,the max floor heave was 312 mm and the max converge nce of the two sidewalls was 111 mm. The convergence speed of the two sidewalls was controlled below1. 0 mm / d mostly and the ultra soft and broken section of the r oadway was controlled below 1. 5 mm/ d. The surrounding rock deformation of the large cross section roadway with the soft and broken surrounding rock was effectivel y controlled.