基于弹性地基梁法的沉陷区埋地管道应力变形分析

场地的不均匀沉降是导致管道破坏的主要原因之一。对沉陷作用下埋地管道进行研究分析,将管道跨越区分为沉陷区和非沉陷区,非沉陷区管道的变形可利用弹性地基梁模型模拟推导出其挠曲线方程,沉陷区管道变形可模拟成三次曲线方程,然后利用边界条件,求得沉陷区管道的内力和位移方程。最后通过实例分析表明:管道的最大应力位于沉陷区与非沉陷区交界面处,且沉陷区管道的最大应力主要由管道内压产生的轴向应力与沉陷作用产生的弯曲应力和轴向应力共同组成,非沉陷区管道主要承受内压产生的轴向应力,故管道内压的影响必须考虑;沉陷量、沉陷区宽度、管径、埋深是影响沉陷区管道变形的主要影响因素,沉陷量、沉陷区宽度的影响最大,而埋深主要影响管道的轴向应力,对弯曲应力基本无影响。

Stress and Deformation Analysis of Buried Pipelines on Subsidence Area by Base Beam Method of Elastic Foundation

The differential settlement of ground is one of the main reasons which causes pipeline damages. The research and analysis on buried pipelines under effect of settlement usually divide the pipeline crossing area into subsidence area and non-subsidence area.Deflection curve equation of deformation of pipelines in non-subsidence area can be simulated and deduced by using base beam model of elastic foundation.Pipeline deformation on subsidence area can be stimulated into cubic curve equation,and then concluded internal force and displacement equation of pipeline on subsidence area by using boundary conditions.The conclu-sions after combining living examples and analysis indicate that maximum stress of pipelines locates on the interface between subsidence area and non-subsidence area.Maximum stress of pipeline on subsidence area is jointly constituted by axial stress caused by pipeline internal pressure,bending stress and axial stress caused by effect of settlement.As pipeline of non-subsidence area mainly suffers axial stress caused by in-ternal pressure,the effect of internal pressure shall be taken into consideration.The principle influence fac-tors that affect pipeline deformation on subsidence area are settlement volume,width of subsidence area, pipeline diameter and burial depth,among which settlement volume and width of subsidence area have the biggest influence,and burial depth mainly affects axial stress of pipeline,which nearly has no influence on blending stress.