Impact of hydro-thermal behaviour around a buried pipeline in cold regions

The lifecycle service performance of infrastructure such as buried pipelines, pavement structures, and building foundations can be adversely affected by the process of freezing and thawing action in cold regions. The complicated and dynamic interactions of the temperature distribution and moisture migration around a buried pipeline, which have a significant influence on the stability mechanism of a cold-region pipeline, play a critical role in crude oil/gas pipeline design in cold regions. In this study, a hydro-thermal coupled mathematical model based on energy and mass equilibrium conservation principles is established for estimating the distribution characters of thermal field and water field around a buried pipeline, and several calculation conditions should be computed to explore the heat-moisture states in the surrounding soils under unfavourable conditions. Subsequently, the optimal methods based on thermal conductivity and thermal insulation thickness are developed, and the relationship among the thermal insulation effect, thermal parameters and thickness can be obtained to evaluate the impact of hydro-thermal behaviour in the surrounding soils in cold regions. Furthermore, this method has potential applications in pipeline behaviour analyses and further investigations in cold regions.