Study On Excavation Simulation And Monitoring Measurements In Construction Of Tunnel In Soil

Based on construction of Tianhengshan tunnel, the paper studies on the choice of excavation methods in tunnel construction and monitoring measurements during construction.In the paper, common excavation methods, main points and attention matters in excavation of tunnel in soil formation were expounded. For the purpose of finding the fittest excavation method of Tianhengshan tunnel, we establish plane elastic-plastic model using finite element program, realizing the releasing of stress after excavation by the method of reversing and releasing the stress, simulate excavation method of step method, heading hole method and mid-wall method, analysis and compare the results such as value and development of stress in formation, deformation and plastic range development, deformation and stress of formation-supporting structure from simulation calculation. And then give the conclusion that the heading hole method is the fittest method by comparing the three methods.Based on the monitoring measurements works in construction of Tianhengshan tunnel, the paper studies on the basic tenets, requirements of instrument, data acquisition, program design and information analysis of monitoring measurements. The main work are ground settlement monitoring, surrounding displacement in the tunnel monitoring, inside displacement of surrounding rock monitoring, stress of supporting structure monitoring, contact stress of surrounding rock and supporting structure monitoring. We establish the method of judging stability of surrounding rock, get the information of surrounding rock deformation trend and supporting structure work state by monitoring measurements, so as to judge the stability of surrounding rock, ensure the safeness of construction, give the time of doing secondary supporting, accumulate information for design and construction in the future.