寒区路基工程与多年冻土间的相互作用分析

A Study on Mutual-affection Between Roadbed and Perennial Frozen Soils

基于Harlan一维水热耦合模型对多年冻土地区水分场、温度场耦合计算进行探讨,建立了水热耦合二维物理模型。对该模型采用伽辽金有限元法和隐式有限差分数值离散,结合某实际高原铁路路基工程进行数值计算,分析了修筑铁路路基对原天然路面热稳定的影响,并对未来十年内全球气候变暖对路基的影响进行了数值模拟,考察了多年冻土上限的变化情况。结果表明:铁路路基改变了原天然地面的传热形式,因而有条件地提高了路基下多年冻土上限,而全球气候的变暖,将对建筑在多年冻土上的铁路路基热稳定性产生影响。

Based on Harlan-one-dimension coupled heat and moisture transference, coupled temperature field and moisture flow in permafrost regions are studied and a two-dimension coupled heat and moisture model is established. An implicit finite-difference and Galerkin finite element method is used to solve differential equations. A numerical example for roadbed of a plateau railroad has been presented, and the effect of global warming on roadbed heat stability and the change of natural permafrost table are also discussed. Numerical results show that construction of roadbed breaks the balance of temperature field and moisture transport of nature, but on the other hand natural permafrost table is enhanced conditionally. However, stability of roadbed constructed on permafrost regions will be inevitably affected by global warming.