地表夯击载荷作用下埋地管道力学分析

为研究地基强夯作业中夯击载荷对埋地管道力学性能的影响，基于有限元原理建立了夯锤-管道-围土耦合三维模型，分析了夯击过程中管道截面变形及所受冲击力变化规律，研究了管道壁厚、夯击速度、夯锤体积对管道应力、应变及变形的影响规律。结果表明:夯击载荷下的管道所受冲击力为脉冲型，且随时间推移逐渐降低为0，最大冲击力随管道壁厚、夯击速度、夯锤体积增大而增大；管道最大等效应力、高应力范围及最大等效塑性应变随壁厚增加而减小，但随夯击速度或夯锤体积增大而增大；随着夯击速度、夯锤体积增大，管道截面变形率（椭圆度或凹陷率）逐渐增大，但其随壁厚增加而减小。

Mechanical analysis on buried pipeline under effect of surface tamping impact load

In order to study the effect of tamping impact load on mechanical property of buried pipeline in the dynamic compaction operation of foundation, a three-dimensional model coupling rammer, pipeline and soil was established based on finite element principle. The variation regulations of section deformation and impact force of pipeline in the tamping impact process were analyzed, and the influence regulations of wall thickness of pipeline, tamping impact velocity and volume of rammer on the stress, strain and deformation of pipeline were studied. The results showed that the impact force received by the pipeline under the tamping impact load is pulse-type, and it reduces to zero over time gradually. The maximum impact force increases with the increase of wall thickness of pipeline, tamping impact velocity and volume of rammer. The maximum equivalent stress, the range of high stress and the maximum equivalent plastic strain of pipeline decrease with the increase of wall thickness, while increase with the increase of tamping impact velocity and volume of rammer. The section deformation rate of pipeline (ovality or sag ratio) increases with the increase of tamping impact velocity and volume of rammer, while decreases with the increase of wall thickness.