Study on range determination and support parameter design of surrounding rock loose zone under multi-criteria

In view of the surrounding rock deformation of transportation roadway in 4108 face of Orchid Yongsheng Coal Industry, especially the large movement of roof and floor, the surrounding rock control technology of transport roadway is studied based on theoretical calculation and on-site surrounding rock deformation observation, and the following conclusions are determined: the surrounding rock loose zone is calculated by Mohr-Coulomb criterion, Hoek-Brown criterion and Mogi-Coulomb criterion. The ranges of the two sides and the roof loose zone under the three criteria are 1.7 m and 2.5 m, 0.47 m and 1.27 m, 1.01 m and 1.81 m respectively, and the average crack development range of the roadway is 2.14 m and the broken section range is 1.74 m. The theoretical calculation is verified, the "anchor mesh cable" is put forward to support the roadway, and the stage deformation of the roadway is determined by on-site roadway deformation monitoring. That is, after the first two stages, the maximum displacement of the roof and floor of the roadway and the maximum deformation of the two sides are 218 mm and 153 mm respectively. In the stable change stage, the surrounding rock deformation of the roadway remains stable. The above research shows that the design support can effectively control the surrounding rock deformation of the roadway.