场地液化条件下埋地弯管道力学反应的数值模拟

基于ADINA有限元分析软件,建立了场地液化条件下埋地弯管的管土接触的土弹簧分析模型.在液化区设置过渡区,考虑非液化区的管土接触作用及液化区土对管道的约束作用,对管道的有效应力及轴向应力进行了分析.结果表明:当液化场地区域存在弯曲管道部分时,弯头处有效应力很大,使其成为整个管网系统中最薄弱的环节之一;弯头壁厚和曲率半径越大,弯管道有效应力越小,说明弯管越不容易发生破坏,有利于抗震;弯头所处液化区的位置距离液化区和非液化区交界处越远,弯管道所受的轴向应力越大,且存在一个最佳位置使得弯头有效应力最小.

Numerical simulation on mechanical responses for buried bent pipe under liquefied field

Based on finite element analysis software ADINA,a pipe-soil contact and soil spring nu-merical analysis model of buried bent pipe in liquefied field was established.Pipe-soil contact in non-liquefied region and constraint effect of liquefied soil on pipe were considered by setting tran-sition zone in liquefied region.Then the effective stress and axial stress of pipe were analyzed.Re-sults indicate that the effective stress of bent part is very large when bent pipe exists in liquefied field.Thus,bent part will be one of the weakest parts in the whole pipe network.The effective stress of bent pipe decreases and the bent pipe is less prone to damage as the wall thickness and curvature radius of bent pipe increase,which benefits earthquake resistance.The axial stress of bent pipe increases as the distance of bent pipe in liquefied region to the interface of liquefied re-gion and non-liquefied region increases,and there exists an optimal position where the effective stress of bent pipe is the minimum.