Study on Support Method Optimization for Large Cross Section Gateway Under Complicaied Geological Conditions

According to the variation and complicated surrounding rock conditions of the transportation gateway in No. 12205 coal mining face of Zaoquan Mine, th e previous support could not effectively control the deformation of the surrounding rock. An optimized study was conducted on the support method of the gateway. The 0 ptimized support method was a multi medium coupling support with bolt 1 steel mesh 1 anchor + grouting + steel beam, steel square support and others. The computer n umerical simulation and the site monitoring and measuring method were applied to the support effect analysis on the support method after the optimization. The results showed that after the optimization of the support method, the convergence between the roof and floor of the gateway was 10 ~ 80 mm, the deformation speed was slow and the deformation of the surrounding rock was in stable. The high stress scope of the gateway surrounding rock was expanded about 1 m and the loose scope of the surrounding rock was reduced to 1. 2~ 2.0 m. The support method optimized could fully play the integrated mechanics effect between the surrounding rock and suppor t mass, the load could be changed as a loading mass and thus the loading capacity of the surrounding rock was enhanced, which would provide good support effect to t he stability of the gateway surrounding rock.