下穿路堤管道力学性状分析

Analysis on mechanical behavior of pipelines undercrossing embankment

下穿路堤管道在上部覆土荷载、路堤堆载、自重荷载等各类荷载的作用下,容易产生拉裂、屈曲等破坏,造成重大经济损失.本文应用ABAQUS有限元软件对长距离输气管道在路堤荷载作用下的力学性状进行分析,探讨了管道埋深、路堤高度、路堤宽度、土体弹性模量和土体压缩层厚度等参数对管道受力性能的影响.研究表明路堤下方管道沿长度方向各截面最大应力、最大应变和竖向位移以路堤中线为轴对称分布.与远离路堤管道段相比,路堤宽度范围内的管道受力有较显著变化,其值与该点距离路堤中线距离成线性反比例增长,在路堤中线正下方达到最大值.管道浅埋情况下不同埋深对管道的力学性状影响不大.路堤高度的增大、路堤宽度的减小会使管道的最大应力、最大应变增加.土体弹性模量的减小、土体压缩层厚度的增大也会使管道的最大应力、最大应变和位移增加.

Subjected to the loads of upside soil, embankment, dead-weight and other loads, the pipeline undercrossing embankment is prone to be cracked by tension and buckled by pressure, which will bring serious economic damages. In this paper,the finite element program ABAQUS was adopted to analyze the mechanical behavior of long-distance gas pipeline with embankment load. The effect of parameters such as the buried depth of pipeline, the 1/eight and width of embankment, the elastic modulus of soil and the thickness of soil compression layer on behavior of pipeline was investigated. Numerical results show that the stress, strain and vertical displacement of pipeline is axisymmetrically distributed taking the center line of embankment as an axis. Compared to that far from embankment, the behavior of pipeline just below embankment has a significant change. The values increase linearly with the decrease of distance to center of embankment and is maximum at the center of pipeline just below the embankment. The buried depth of pipeline has a little effect on the mechanical properties of pipeline when pipeline is shallowly buried. The increase of the height and the decrease of the width of pipeline will make the stress, strain and vertical displacement of pipeline increase. Also, the decrease of the elastic modulus of soil and the increase of soil compression layer thickness will lead to the increase value.