地震波作用下地下管道试验的数值模拟方法

Numerical simulation of test on underground pipeline excitated by seismic wave

以模型试验几何尺寸建立有限元数值模拟模型,全面给出了地下管道地震动作用的三维有限元建模及分析研究的主要步骤,建立柔-柔接触面来反映管-土相互作用,利用拉格朗日乘子法求解接触效应;通过ANSYS和MATLAB的交互使用,对土体四周及底部定义的粘弹性边界实现能量辐射,减小边界效应;考虑试验模型与实际模型的比例,对原始地震波加速度时程曲线进行缩尺处理,模拟得到的管道响应规律与试验结果吻合较好,表明该数值模型是合理的。在此基础上讨论了管道在地震波作用下的位移、加速度和应力的动力响应,并提出了相关实用的工程建议,为地下管线等长线型地下结构的地震响应理论分析提供参考。

This paper thoroughly researches the process of three dimensional finite element modelling and analysis of underground pipe subjected to seismic dynamic effect, which served as reference to the seismic analysis of large- length underground pipe. The Drucker-Prager constitutive model was adopted to consider the non-linear behavior of the soil, flexible-flexible contact was built to consider the soil-pile interaction, further, the Lagrange method was adopted to solve the contact problem. Through the interchangeable application of ANSYS ＆ MATLAB, the viscoelastic boundary was imposed on the model boundary to realize energy radiation and reduce the boundary effect. Con- sidering the scale ratio between the prototype and calculation model, scale process was conducted on the original time history acceleration curve. Finally, the dynamic response law of the underground pipe, including the displacement, acceleration and stress are researched, and some related engineering suggestions are proposed to give a veference to seismic response analysis of large-length type structures, such as underground pipeline.