Research And Application On Monitoring Technology In Shield Tunnel Construction

With the rapid economic development of China, there are more and more large-scale tunnel projects under construction. As an important method of safety insuring, design optimizing, construction instructing, progress of monitoring and measuring technique is a matter of great significance for tunnel construction. Nowadays, there are lots of problems still exited in engineering practice. Combined the Nanjing weisanlu urban underwater tunnel, the factors influencing the stability of segment, the interaction mechanism of internal structure in the shield tunnel, the deformation and internal force of segment structure and the grouting effect are studied by theories analysis and numerical simulation. The main research is as follows:(1)According to the design and construction information, the influence factors of risk and the potential consequences of nanjing weisanlu urban underwater tunnel are assessed by expert investigation, and the control measures are proposed.(2)Considering adverse conditions, such as geological conditions, hydrological conditions and the characteristics of underwater large-diameter shield tunnel, the weakness of shield structure is found. Double lane is adpoted by Nanjing weisanlu urban underwater tunnel. The design and construction experience is lack in our country.And the interaction mechanism between internallane plate, segment and formation are on research. On account of it, the contents and key points are finalized, which provide evaluation index of monitoring pointed objects.(3)Combined the Nanjing weisanlu urban underwater tunnel, this paper elaborates the monitoring project, the instrument selection, the measuring point layout and the monitoring method.(4) Based on the tunnel segment lining site monitoring, the paper numerical simulates and analyses the internal force of the shield segment by finite element software through selecting several special sections. At the same time, the deformation of shield segment and grouting effect are collected. The result determines whether the structures meets the requirement, and provides an important reference for better and more reasonable construction.