Abstract:
Aiming at the difficult problems associated with the time-sensitive large deformation of the high stress soft rock roadways in the 1 000 m or more deep coal mines,according to the underground monitoring data and support states,the characteristics of large strata deformation,bolting component damage and failure under different methods of supports were obtained through underground survey and analysis on the soft rock roadway in the Kouzidong coal mine, China. The vertical reaction force,horizontal thrust and bending moment of the U-shaped steel arches under uniformly distributed loads and different types of concentrated loads bearing conditions were gained by theoretical calculation, which revealed the enhancing function mechanism of the filling on the bearing capacity of the U-shaped yielding steel arches. The effects of three support patterns for controlling the surrounding rock deformation and failure,which were the support by rock bolt-mesh-shotcrete,the support by rock bolt-mesh-shotcrete combined with steel tubs filled with concrete and the support by rock bolting,U-shaped yielding steel arches and back filling in synergy,were compared through the numerical simulation,and the principle of the soft rock roadway control by rock bolting,U-shaped yielding steel arches and back filling in synergy in 1 000 m or more deep coal mines was illustrated. On the basis of introduc- tion from abroad and independent research and development,the roadway control technology by means of rock bolting, U-shaped yielding steel arches and back filling in synergy including support materials and components,filling materials and system,automatic U-shaped yielding steel arch installation machine and the monorail roadway bolting operation platform was developed. Based on the achievements mentioned above,the rock control pattern and parameters were put forward with rock bolting,U-shaped yielding steel arches and back filling in synergy for the experimental roadway in Kouzidong coal mine,and the field experiment and monitoring were conducted. The monitoring data show that the road- way control technology by means of rock bolting,U-shaped yielding steel arches and back filling in synergy could ef- fectively control the large roadway deformation in the 1 000 m or more deep coal mines,especially the time-sensitive deformation,which made the roadway maintain stable for a long time. Compared with the effect of original support,the roadway deformation decreased by more than 90% and the cost for the roadway maintenance were reduced simultane- ously,which provided an effective measure for the soft rock roadway control in 1 000 m or more deep coal mines.