Stress analysis and design on the pipeline support in the underwater shield tunnel

In this paper, the Yellow River shield crossing project of Third West-to-East Gas Pipeline in Zhongwei was taken as the example to realize the target of precise design on the pipeline support in underwater shield tunnel. The stress and displacement of the pipeline in the whole crossing section was analyzed by using CAESAR_II software, to provide the guidance for pipeline support design. At the crossing section of Yellow River shield tunnel in Zhongwei, the design pressure is 12 MPa and the pipe diameter is 1 219 mm. The horizontal projection between the shaft centers on both sides of the shield tunnel is 450 m long. The space for the Fourth West-To-East Gas Pipeline is reserved in this shield tunnel. The pipeline in the shield is installed in the patterns of vertical shaft installation and tunnel lane installation. The pipeline in the vertical shaft is taken as the whole pipeline of crossing section for compensation calculation. In the tunnel lane, all gas pipelines are installed on the available reinforced concrete support. The Third and the Fourth West-to-East Gas Pipelines are laid in parallel with the center distance of 2.08 m. The spacing between supports is 15 m along the axial direction of the pipe. Insulating rubber plate of 10 mm thick is set between the pipe and the support. The pipeline is fastened with pipe clamp to prevent the pipeline from moving and floating. One anchor block is set respectively on either side of the shaft, 25 m away from its center. The Third and the Fourth West-to-East Gas Pipelines share one anchor block. The spacing between the support pipe clamp and the pipe is calculated by software and the displacement of the pipeline is simulated, so that the pipeline support is designed more precisely.