基于水热耦合分离冰冻胀理论的冻土冻胀力响应研究

Project structures were seriously destroyed and project environment was deteriorated by the frost heaving in seasonally frozen regions and permafrost regions. The current findings on frost heaving force can not fully reflect the fundamentals to the frost heaving force and the coupling effects between the frost heaving and structure deformation, and that can hardly supply an exact understanding to the fundamental problems. The key perspective is aiming at th0e coupling mechanism and the corresponding effects between frost heaving of freezing soil and project environment. The present investigation object is the system of the frozen soil and project environment and the research emphasis is put on the evolution mechanism of the frost heaving force and the corresponding evolution laws. The comprehensive research methods including numerical simulation tests, sample test and model test will be used. The experimental model will be established by analyzing the properties of the typical project and physical characteristic of the frozen soil -structures interaction. The research on the relationship between frost heaving force and environmental variant including soil type、freezing conditions and constrain conditions is then be carried out. The frost heaving response model system will be developed by introducing the frozen soil-unfrozen soil-structures interaction model based on the current separated ice model coupled heat and moisture transfer. In the end, the frost heaving force forming mechanism and evolution laws will be interpreted and the simple method for computing frost heaving force of typical project will be put forward. The anticipated achievement will provide a scientific support for stability for frozen soil project and frozen wall.

天然冻土和人工冻土冻胀及其诱导的冻胀力严重破坏工程结构、恶化工程环境，既有冻胀力研究成果尚未完全揭示冻胀与工程结构形变的耦合作用的特性和非线性行为，难以形成对冻胀力基本问题的准确理解。课题紧紧围绕冻土冻胀与工程环境（结构、介质）耦合作用机理及效应这一冻胀力研究的关键科学问题，以冻土与工程环境整体体系为研究对象；以冻胀力形成和演化的机理、特征与规律为研究重点；采用理论分析、数值计算、试样试验和模型试验相结合的综合方法；抽象典型工程中冻土-工程结构相互作用的物理特征，建立试验及分析模型，研究冻胀力与土性、冻结条件、水分补给以及工程结构约束特性等环境变量之间的基本关系；修正与完善既有水热耦合分离冰冻胀模型，耦合冻土-未冻土-结构相互作用基本模型，寻求建立冻胀力响应的数学力学模型体系，基本阐明冻胀力形成机理和演化规律，获得典型工程条件冻胀力的简化计算方法，为冻土工程和人工冻结工程稳定提供科学依据。

本项目针对冻胀及其诱导的冻胀力严重破坏工程结构、恶化工程环境问题，项目围绕冻土冻胀与工程环境（结构、介质）耦合作用机理及效应这一冻胀力研究的关键科学问题，以冻土与工程环境整体体系为研究对象；以冻胀力形成和演化的机理、特征与规律为研究重点；建立了水热力耦合的分离冰模型，抽象典型工程中冻土-工程结构相互作用的物理特征，开展了法向冻胀力与一维冻胀变形的关系和冻土与基础 切向冻胀力模型试验研究，基本阐明冻胀力形成机理和演化规律，获得典型工程条件冻胀力的简化计算方法，为冻土工程和人工冻结工程稳定提供科学依据。