冻土区路基与埋地管道水热变化模拟分析

Water and heat distribution analysis of subgrade and pipeline in permafrost regions

为研究冻土区工程水热分布规律,基于不饱和土Richards方程推导出了冻土水热变化的耦合关系式。应用有限差分原理进行离散化,编制计算程序,对中俄输油管道漠大线进行模拟。通过模拟结果与实测数据对比验证了应用模型计算程序的可靠性。应用程序分别对冻土区路基与埋地管道的水热分布变化进行模拟分析。对于冻土区斜坡路基:冻土斜坡路基的融化界面随时间增加而逐年降低,融化界面与水分富集层位置相近,均呈倾斜分布,影响斜坡路基的稳定性。对于冻土区埋地管道:管道长期运营加剧其周围多年冻土上限下降,管道附近10年后的下降约为天然情况下的4倍。

To study the water and heat distribution of engineering in permafrost regions. A coupled model for frozen soil is established based on the unsaturated soil Richards equation. The model is discretization using finite difference method,and the calculation program is got. The temperature of frozen soil around China-Russia oil pipeline 'Mohe-Daqing'is simulated. The contract result between simulation and monitoring data shows that the program based on the model has a high reliability and accuracy. The program is used to simulation 10 years water-heat change of subgrade and pipeline in permafrost region respectively. It shows that: the location of subgrade melting interface gets lower with time increase.The melting interface and moisture accumulation layer along the slope are not horizontal,this must cause more effect on the subgrade stability. The pipeline gives a nearly 4 times permafrost table decline value than that under nature condition after 10 years.