Creep simulation on fractured surrounding rock of large section chamber and its control technology

摘要: To large section chamber with fractured surrounding rock and repeatedly repairing,strong rheology cannot be controlled effectively bolt-wire-cable support style.According to the repairing 39# pump house of Zhongmacun Colliery,Jiaozuo Coal Company,the main factors on instability include strong strata influenced by high stress,uneven loading steel timbers.Repair scheme combined initiative passive is proposed,which includes primary bolt-wire mesh-cable,secondary closed timber third grouting reinforcement.Original analyzed creep numerical simulation.The results indicate that shrinkage percentage 92.2% within 360 days,and maximum roof subsidence 2 792 mm,and accelerated phase appears.The 56.8 mm 1 000 stable appears method.Cables are anchored in intact mass,but most bolts plastic zone.Density stress contour lines very intensive outside range,whose peak value increasing moving gradually deep extension time.The field experiment shows displacement 18 convergence ratio less than 0.5 mm/d after 224 days.So repair successful.