Study On Risk Evaluation And Control Technology For Large-Diameter EPBS Crossing The Guitang River

With China’s rapid economic development and increasingly accelerated pace of urbanization, underground rail traffic into the high-speed development period. The shield method is widely used in tunnel project such as the subway tunnels, urban highway tunnel and the tunnel crossing rivers and lakes. Meanwhile, the construction of shield tunnel also has many unsolved problems need to be further studied. For example, the large diameter earth pressure balance shield underneath pass the river has constructional risk, and the current related research is little in domestic. Therefore, it is necessary to study the risk control about the large diameter earth pressure balance shield underneath pass the river.In this paper, combined with the engineered example of the large diameter earth pressure balance shield underneath, pass Guitang River, the paper carried out the following researchs:(1) The construction of the project risk environment and risk factors were analyzed, and the corresponding risks were classified. Using the fuzzy comprehensive evaluation model, I analyze the probability of occurrence of basic risk factors and the resulting impacts on the risk of loss on the construction process. Besides, I determine the shield tunnel constructional risk rating through a combination of quantitative and qualitative.(2) In view of the construction section about the large diameter earth pressure balance shield tunnel underneath pass the Guitang River, I propose an overall scheme of construction, and then combined with the surrounding environment around the tunnel to analysis the measures of the risk control aim at parameter setting, axis control, soil improvement, synchronize and secondary grouting, the measures of shield tail brush and the maintenance about equipment. Therefore, the safety of construction is guaranteed.(3) According to the several key parameters, such as the hogging or hanging of ground, the horizontal displacement, internal force and deformation of lining ring, I establish a monitoring management. Then, I analysis the effects of risk control about the large diameter earth pressure balance shield tunneling underneath pass Guitang River. The results show that we can ensure the shield through the river sections safely by using the measures of risk control such as parameter setting, axis control, soil improvement, synchronize and secondary grouting, the measures of shield tail brush and the maintenance about equipment in the construction of the large diameter earth pressure balance shield underneath pass the river.There are26pictures.16tables and36references in this article.