Study On Monitoring Measurment Technology And Security Of Second Lining In Heluoshan Tunnel

In company with nonstop rushing of the long-span tunnel construction, the demand of the present design and construction code is already insatiability with the need of long-span tunnel engineering design and construction. Consequently, it was for the present urgency problem on that how about long-span tunnel.The tunneling monitoring measurment and information feedback technology is one of the three major pillars to construct tunnels using the principle of the new Austrain tunneling method (NATM). The theoretical foundation of NATM is that the bearing capability of surrounding rock by oneself is brought into full play to the maximum, protect the original intensity of surrounding rock of the tunnel as much as possible, to allow deformation of the surrounding rock but unlikely to form relaxing destruction and it is out of shape but present strong that grasp the surrounding rock and prop up and protect the dynamic tunnel out of shape to excavate and prop up the principle protected in time deform keep dynamic balance between the deformation of surrounding rock with structure supporting oppose energy which restraines the deformation ,make the construction method have good suitability and economy. So tunnel monitoring measurment is the foundation and prerequisite of tunneling with NATM.The paper studies the railway tunnel monitoring measurment and information feedback deeply, combining the tunnel project from Dali to Lijiang in YunNan Province. The tunnel monitoring measurment includes the compulsory measurmental contents and the optional measurmental contents. The author makes the research as follow: Basic principle and demand of monitoring measurment and request, monitoring measurment data information gathering, monitoring measurment scheme design, monitoring measurment data information analysis and feedback, and emphasis is put on the latter. The focal point of the research is put in the monitoring measurment information analysis and feedbacks. According to the monitoring information especially displacement information to carry on statistical analysis. From theory of experience feedback and can hold the deformation of surrounding rock and tunnel structure and receive the strength law, confirm the stabilities of surrounding rock and tunnel structure, confirm rational opportunity of protecting and the parameter of protecting, pursue economy on the basis of safe construction.Through monitoring and information feedback, the tunneling security has been offered important technical and theory support and offered the reliable technological basis for optimization of tunneling design parameter.