岛状多年冻土管道周围热-水-应力耦合数值模拟

考虑大气温度以及管内流动介质温度的影响，建立由多个土层构成的岛状冻土物理模型，研究塔河地区埋地输油管道周围热-水-应力（T-H-M）耦合作用，分析水-热-应力耦合作用下管道的受力情况并进行管道强度验算。采用多物理场耦合软件COMSOL Multiphysics进行数值模拟，计算在T-H-M三场耦合及非耦合两种工况下岛状多年冻土管道周围应力和沉降曲线等。分析比较表明，岛状多年冻土区的温度，冰水相变以及水分迁移对应力场存在较大的影响；水分场、温度场以及应力场三者之间耦合作用明显；岛状冻土随季节呈周期性冻融，管道周围出现较大应力集中和沉降现象，会对管道安全产生一定影响。

Numerical simulation of thermo-hydro-mechanical coupling around underground pipelines in patchy permafrost region

Building a patchy permafrost physical model, which is composed of multiple formations, the paper researches the effect of thermo-hydro-mechanical(T-H-M) coupling around the buried oil pipelines in Tahe on the base of considering the effect of environmental temperature and flow medium temperature in the pipelines, and analyses the stress of the buried pipelines and takes a strength calculation on the pipelines. The distribution of stress and sedigraph are acquired by the multiphysical fields coupling COMSOL Multiphysics software, which is used to simulate two kinds of working condition of T-H-M coupling and uncoupling. The numerical simulation results indicate that temperature, water phase transition and water migration influence the stress field greatly. What’s more, the coupling among the moisture field, the temperature field and the stress field is very remarkable. Because of temperature change, patchy permafrost takes on freezing or thawing, which results in stress concentration and settlement around the pipelines, so as to harm the safety of buried pipelines.