关键词: Pasternak模型, 修正Vlasov模型, 弹性系数, 土中剪力, 剪切系数

Abstract: The vertical displacement of soil in the underground pipeline caused by the construction of shield tunnel was studied based on the Loganathan function. The Pasternak model considering shear transfer in soil was used to simulate the pipeline-soil interaction. The key parameters of the Pasternak model—elastic coefficient k and shear coefficient gs were solved by using the iterative procedure in the Modified Vlasov model. The calculation results were compared with the results of existing literatures and engineering monitoring data, and the differences between the proposed model and the existing result were also explored. Furthermore, a parametric study was conducted to analyse the influence of soil shear stiffness, cross angle, soil modulus and tunnel radius on the pipeline-soil interaction. The results show that the values of spring factor k and shear stiffness factor gs solved via the iteration procedure can improve the accuracy of the Pasternak model; the influence of soil shear resistance on the calculated vertical displacement of pipeline is up to15.3%; with the decreases of cross angle between the pipeline and the tunnel, the vertical displacement of pipeline increases and bending moment decreases; the increase of soil elastic modulus and the tunnel radius will increase the vertical displacement and the bending moment of pipeline.

Key words: Pasternak model, modified Vlasov model, elastic modulus, soil shear resistance, shear stiffness factor