Research on the Support Parameters Optimization of Large Section Roadway in Shallow Coal Seam

To explore the optimization design method of reasonable support parameters for large section roadway of shallow coal seam in Yulin area, this paper takes the support parameters of 3 -1 coal return air roadway in North Second Panel of Hongliulin Coal Mine as the research object.The length, diameter and row spacing of anchor rods needed for support of return air roadway are calculated by using suspension theory.Combined with the calculation results, the use of the roadway and the specific engineering geological conditions in the excavation construction, the roadway size and support parameters are optimized.The numerical simulation of FLAC 3D computer shows that the plastic failure range and deformation displacement of surrounding rock of optimized support scheme meet the requirements of roadway use.The monitoring results of loose zone, and anchorage force in the engineering site show that the loose circle of roadway roof is 1.23 m, and the loose circle range of roadway side is 0.72 m.The anchoring force of roof bolt reaches 50 KN, that of front and auxiliary walls is 26 KN and 21.2 KN respectively, and that of anchor cable is 189 KN.The loose zone depth and stress intensity of anchor cable of the optimized support scheme all meet the use requirements of return air roadway.It improves the tunneling efficiency, shortens the construction period, reduces the support cost, and improves the economic benefit.It provides reference value for the optimization design of roadway support parameters in similar production coal mines.