Abstract: The equivalent discrete lumped mass model with multi-degree of freedom for the long-distance buried pipeline is proposed in this paper to evaluate the longitudinal dynamic of the pipeline. The proposed model is able to use the non-uniform excitation as the inputs by considering the traveling wave effect along the longitudinal direction of the pipeline. Moreover, the ideal elasto-plastic constitutive relation of the soil-spring model is used to simulate the slip effect between the pipe and the soil under seismic loading. Based on the longitudinal seismic displacement input, the displacements of the lumped-mass point and the relative displacement between pipe and soil can be obtained. Moreover, the internal force and deformation of the pipeline can be obtained by analyzing the force-displacement relation between every two lumped-mass points with the structural mechanics method. Finally, the accuracy and the efficiency of the proposed method is validated by comparing with the finite element analysis results of the continuous pipeline.

Key words: long-distance buried pipeline, lumped-mass model, the ground motion non-uniform input