X70 Steel Tunnel Pipeline Design Construction Mechanical ParametersOptimization Analysis and Application

摘要

An optimization method is presented for X70 steel tunnel pipeline designrnconstruction based on an analysis of mechanical issues. Considering thernSichuan-to-East-China Gas Transmission Project tunnel pipelines, two modes forrnplacing the long distance large diameter tunnel pipeline are studied, includingrnbuttress placement and embankment buried placement. Using the principle of virtualrnwork, a formula is derived for determining the push force of pipeline anchor block atrnthe tunnel exit. The tunnel pipeline placement parameters are analyzed consideringrnvertical and horizontal bending, using an elastic stability model and the energyrnmethod. The parameters consider multi-span continuous beam stability, span length,rnplacement length for stability, radial and upheaval stability. The formulas arernpresented as a function of the various parameters. Based on the research results, arncomputer program has been developed. The key mechanical parameters for therntunnel pipeline design construction of the Sichuan-to-East-China Gas TransmissionrnProject are optimized. Applying a commercially available pipeline finite elementrnsoftware tool, the entire design scheme has been analyzed for pipeline stress andrndisplacement in order to verify feasibility of the placement parameters. The resultsrnshow that the design construction parameters optimization method for tunnelrnpipelines can satisfy engineering design requirements.