纵向非一致地震激励下管-土结构响应的简化分析模型

A simplified analysis model for pipe-soil structural seismic responses under longitudinal non-uniform seismic excitations

将长输埋地管道化为多自由度体系的等效离散集中质量模型,建立了集中质量模型在管道纵向荷载作用下的结构响应计算模型。模型考虑了沿管道长度方向的行波效应,实现了不同质量点处地震动的非一致输入,为考虑管-土相互滑移的影响,模型中考虑了土体的弹塑性本构关系。模型以纵向地震动位移输入,求解得到管道各集中质量点的位移和管-土间的相对位移,在此基础上运用结构力学方法对每两个集中质量点间管道进行精细分析,进而求得管道的内力和变形。通过算例分析,集中质量模型程序计算结果与连续型管道的有限元分析结果进行比较,验证了集中质量模型方法的有效性和合理性。

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.