考虑覆盖效应的路基水热传输及冻胀过程多场耦合分析模型及方法研究

There are a vast area of seasonally frozen soil in China. Frost heave and thawing settlement of seasonally frozen soil may cause unacceptable damage to the engineering facilities constructed thereon. This is especially true for highways and high speed railways, constructed in a large scale nowadays in China, as they are quite susceptible to foundation deformation. Most of the current research concentrates on the freezing process and possible frost heave for soil which is fully or partly saturated with water. This cannot explain the significant frost heave noted in northwest China where it is dry and lack of rain. Recently the discovery of the Canopy Effect in road foundation and the development of theory for multi-field coupled analysis have offered possibility for a systematic in-depth study of this problem. This research project proposed intends to perform in-depth quantitative analysis of water-heat transfer and froze damage in railway embankment by using the water-vapor-heat-force coupled analysis theory combined with indoor experiments and in-situ measurements, so as to provide scientific support for the prevention and mitigation of frost damage for the road foundation. This is believed to be meaningful for the relevant theory development as well as for the engineering practice.

我国有大面积的季节性冻土区，土的冻融对建于其上的工程设施可造成不可接受的严重危害，特别是对近年来大量兴建、对路基变形敏感的高速铁路和高速公路。目前已有研究多集中于含水土层的冻结过程以及可能发生的冻胀变形，这难以解释西北干旱少雨地区某些铁路和公路路基所发生的严重冻胀变形。近年来路基土体“锅盖”效应（覆盖效应）的发现以及多场耦合分析理论的发展，为该问题的进一步深入系统研究提供了可能。本项目拟在已有工作的基础上，针对路基冻害问题，发展基于水-气-热-力多场耦合分析理论的计算模型和方法，结合试验实测，深入定量分析研究铁路路堤内水热传输和发生冻害的规律，从而为制定有效可行的路基冻害防治措施提供科学依据。相信该项研究在有关基础理论及工程实践方面均有重要意义。