Study On The Surrounding Rock Controlling Technology Of Floor Roadway Under Closed Distance Coal Seam Group

Exploiting coal seams group is different from exploiting single coal seam, surrounding rock of roadwy under coal seams group was strong effected by dynamic pressure in the process of exploiting coal seams group respectively, distortion of surrouning rock mass is more bigger than that of exploiting single coal seam,so deformation of surrounding rock mass is hardly controled by generally method. Study on basic law of stress field and new supporting method are terribly necessary in the process of exploiting upper and lower local seam.Features of stress field of surrounding rock mass were analyzed in different vertical distance and different position of mining face in exploiting upper and lower coal seam respectively in this dissertation. The most strongest position of effect were confirmed by vertical distance and position of minin face. In this condition,features of stress field were analyzed in different lithologic layering of surrounding rocks.A computational rock mechanics software, FLAC2D/ FLAC3D, was introduced to simulate the feature of stress field in different vertical distance and position of mining face. Features of U-steel and features of U-steel coupling bolt were simulated in different lithologic layering of surrounding rocks. And U-steel coupling bolt supporting were consider with better effect in controling deformation of surrounding rocks. On the base of this,parameters of bolt supporting were optimized by orthogonal design and best controling scheme were put forward by numerical simulate in orthogonal design and the scheme was constructed in practical project and surrouding rocks were better controled.