Study on Surrounding Rock Deformation Mechanism and Control of Roadway with Large Section and Extra-Thick Top Coal

In order to solve the problem of safe and rapid excavation support roadway with large section extra-thick top coal under complex geological conditions, deformation mechanism control are analyzed by means field investigation, numerical simulation, theoretical analysis, practice, taking 2203 transportation a mine in Shanxi Province as engineering background. The results show following: (1) concentration normal tensile stress middle large-span roof end shear is significant, which may easily lead separation extrusion surrounding rock; (2) surface failure depth side large, insufficient length bolt, small density protective side, strength easy cause bulge splitting wall; (3) joints fractures developed, dirt band different thickness occurs, so it for anchor solids cut down along weak band; (4) structure produces horizontal movement rock, leads poor supporting effect material failure. Finally, economic comprehensive system “high-strength, high-resistance, high-prestressed cable + high-strength two sides U-shaped combined truss” proposed, explained applied successfully field.