地基差异沉降下埋地管道的有限元分析与试验研究

Finite element analysis and experimental research on the buried pipelines in case of uneven settlement of the building foundation

利用大型数值模拟仿真软件ABAQUS对地基差异沉降下的埋地管道力学性状进行了分析,找出了管道受力较大的区域。采用电测法对地基差异沉降下的埋地管道受力状况进行现场测试,结果表明,有限元计算结果与试验吻合良好。对管道每隔1个月连续进行4次应力测试,得知地基差异沉降下管道所受的应力远小于管道材料的许用应力。分析了埋地管道受力影响因素。可以为地基差异沉降下埋地管道最大应力区的有效防护提供参考。

This paper is dedicated to the study of the stress of buried pipelines to find the regularity of the pipeline-soil interaction under the foundation of uneven settlement through finite element analysis In DOing our research, we have adopted electrical measurement method to monitor the mechanical behavior of the buried pipelines in case of uneven settlement of the building foundation. As is known, buried pipelines are the material basis of urban survival and development. A considerable number of buried pipelines are laid down over the soft soil underground basis of a non-linear and uneven settlement, making the mechanical analysis complicated. Actually, high-stress areas of pipelines were found in the intersection connecting the pipelines on the surface as well as the buried pipelines. Therefore, it would take four months to complete a circle of successful monitoring work of the pipelines. The test results have shown that the stress of the buried pipelines tends to become greater and greater with the uneven settlement of foundation, which indicates that the pipeline-laying stress seems to be greatly influenced by the uneven settlement of the foundation. However, when the mechanical behavior of the buried pipelines in the case of the foundation uneven settlement was analyzed by using numerical simulation and emulation software ABAQUS, it proves possible to gain the uneven settling amount of the foundation needed in the finite element analysis from the test. Furthermore, the initial conditions of the finite element analysis turn out to be in accordance with the experiment. The results of finite element analysis also prove to be in conformity with the experimental results except for the place of pipeline with portiforium and fluid impact. In addition, we have also analyzed the influential factors of the buried pipelines stress. The resuits show that the main factor of the fluctuation of pipes stress comes from the vibration of the internal pressure. But the vibration of internal pressure was not the main factor of the pipeline-soil interaction. Deformation modulus and position ratio, which serve as the main factors of the pipeline-soil interaction, have actually little influence on the piping stress. Thus, the paper has developed a stress analysis and numerical simulation method of the stress of buried pipelines in case of uneven settlement on the basis of our research work in hoping to provide an excellent technical support for the mechanical analysis and safety evaluation of buried pipeline stress.