Optimization Analysis On Design Parameters Of Cross River Shield Tunnel For Oil And Gas Pipeline

With the construction of railways, highways, subways and various municipal works and underground pipelines, a great variety of underground space engineering have been buiding,and ancillary working shsftss have also become the necessary access to connection between the ground and underground spaces. The safety and stability of these subterrenaean works become more and more important. In order to analyze the structural design characteristics of the shield tunnel for laying oil and gas pipeline, combined with the actual situation of the design and construction of the Nantanhai Shield Tunnel in the second phase of the Guangdong Provincial Pipeline Network, the working shaft and its enclosure of the Nantanhai slurry shield tunnel, the main method and related parameters of the optimal design of the shaft and the segment of the shield tunnel are obtaiend through the analysis of the test results so as to provide a suitable method for the future similarity of the oil and gas pipeline.The structure design of the river shield tunnel provides guidance. The main research contents and results are as follows:(1) In-situ monitoring of the working shafts and their enclosures in the Nantanhai slurry shield tunnel and the formation pressure of the tunnel lining of the river bottom section are tested, including the underground continuous formation pressure, the inner lining formation pressure and the distribution of formation pressure in the bottom of the shield tunnel.(2) Using ANSYS numerical simulation software, combined with the field tested pressure data, according to the mechanical model of plane strain problem, the deformation and deformation of the underground diaphragm wall of Nantanhai shaft are measured under the condition of stable formation pressure,as well as bending moment,axial force and shear force.(3) According to the calculated internal force, and considering the "Railway Tunnel Design Code" for the safety factor calculation, the work of the underground diaphragm wall,the inner lining and the river bottom tunnel segment structure are in safe status.(4) According to the calculation results and engineering practice, the parameters such as the underground diaphragm wall, the inner lining and the thickness of the river section tunnel are optimized to ensure its safety and reliability.