Shuangbei Tunnel Blasting And Vibration Monitoring Technology Of Construction

Traffic tunnel in china develops rapidly because of the country's investment in transportation infrastructure construction.Tunnel construction is facing a severe test,many problems need to.be solved urgently.In the background of Shuangbei tunnel in Chongqing,this dissertation studied the construction technology of the portal,the optimization of blasting plan,the detection of blasting vibration and the protection of the environment in a large section tunnel with weak surrounding rock.The portal is always the key points of tunnel construction,to ensure the safety of the construction of the portal is the beginning.Compared with other sections,the portal has its own characteristics,rock weathraing conditions of the portal is generally heavier,the lining often has a serious problem of shallow bias.Considering the poor geological condition of the portal,in the construction of Shuangbei tunnel,excavation after support is used.In the process of tunnel excavation,in order to reduce the vibration of surrounding rock as far as possible,and give full play to the bearing capacity of surrounding rock,the blasting plan of Shuangbei tunnel excavation is optimized as required,there are four plans for all kinds of surrounding rock.The blasting vibration monitoring results show that the blasting vibration velocity is reduced by about 75%after the blasting plan was optimized.The optimization is effective.In the process of excavation,the blasting vibration of tunnel construction is tested.8 monitoring points were arranged near the tunnel.In addition,when the tunnel face is close to the railway,the railway was monitored.Near the Shuangbei tunnel,there are railway,schools and residential areas,so,the environment problem like slung shot,shock wave,noise and dust are studied also.Through the above study,we hope to provide reference for construction of large section tunnel with weak surrounding rock.