液化土中输流管道的竖向地震响应研究

砂土液化是埋地管道遭受地震破坏的主要原因之一。液化土对管道产生上浮力,使管道发生上浮反应,它是随地震发生时间而变化的动态过程。将地震载荷作用下的液化区埋土管道模拟成两端弹性支承的直梁模型,考虑管-土间的相互作用和管内流体与管道之间的流固耦合作用,采用模态叠加法对液化区埋地管道进行地震响应的动态分析,探讨了管道和液化土参数对管道动态上浮反应的影响。通过数值仿真得到了管内流体的流速、流体压力、流体密度、管截面轴向力,管道黏弹系数、液化土容重和相对弹簧系数、地震加速度幅值等因素对管道上浮位移的影响情况。

Study on seismic response of buried pipeline in liquefied soil

The liquefied soil will do great damage to buried pipeline during an earthquake.It causes a floating force and leads to floating response that is a dynamic process varying with time.Simplifying the underground pipeline in liquefied soil under the action of seismic loading as a model of a simple beam with elastic supports on two ends and considering the interaction of buried pipeline-soil and fluid-structures,the authors use the mode superposition method to analyze the dynamic seismic response.The influence of various pipeline and liquefied soil parameters on floaing response was discussed.The dynamic floating displacement of pipeline and how it varies with the parameters of flow velocity,fluid pressure,fluid density,axial force of pipe section,damping of pipe material,the specific gravity and relative elastic coefficient of liquefied soil and the amplitude of seismic acceleration was calculated and analyzed.The results indicate that the dynamic seismic response analysis method is successful and meaningful.