Multiscale modeling of geomaterials subjected to environmental loads

环境载荷作用下岩土材料的多尺度建模

• 批准号: 5905-2013
• 负责人: Pietruszczak, Stanislaw
• 金额: $ 1.75万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=662177
• 关键词: Multiscale; modeling; geomaterials; subjected; environmental

The proposed research is related to modeling of mechanical and hydraulic response of geomaterials subjected to environmental influences. It is recognized that climate change will have a direct impact on a wide range of physicochemical processes in soils thereby modifying their microstructure and affecting their properties. Therefore, the focus in this research is on the response of soils to extreme weather conditions, viz. moving freezing front and a heavy rainfall. The major topics that will be addressed include: (i) modeling of the mechanical response of frost-susceptible soils, (ii) modeling of the chemo-mechanical interaction in soils due to increased rainfall and (iii) influence of evolving microstructure on the hydraulic/strength properties of soils.**Re.(i) Frost heaving and thawing is a major cause of damage to infrastructure and landforms (e.g. debris flow) in regions of seasonal frost. The primary objective of this research will be to develop a framework for describing the deformation process in both in-situ frozen soils as well as soils containing ice lenses. This framework will be employed to model the effects of frost heave on the integrity of oil/gas pipelines.**Re.(ii) Intense precipitation often leads to a loss of stability of geotechnical structures, in particular that of natural slopes and embankments in cohesive soils. Specification of properties of these soils is difficult as it involves a complex system of mineralogical and chemical factors. The approach implemented here will be based on a framework of chemo-plasticity. The governing equations describing the transient hydro-chemo-mechanical coupling will be applied to examine the stability of slopes subjected to a rainfall. **Re.(iii) The environmental loads, viz. temperature and precipitation, can significantly alter the microstructure of the material, which often leads to anisotropy at the macroscale. The main objective of this work will be to introduce tensor-valued descriptors of material fabric, establish appropriate evolution laws for these measures and incorporate them in a macroscale framework. **The results of research will contribute to both fundamental knowledge as well as practical engineering aspects.****************

拟建的研究涉及岩土材料在环境影响下的力学和水力响应建模。人们认识到，气候变化将对土壤的各种物理化学过程产生直接影响，从而改变其微观结构并影响其性质。因此，本研究的重点是研究土壤对极端天气条件的响应，即移动的冻结锋和强降雨。将讨论的主要主题包括：(i)易冻土壤的力学响应建模，（ii）由于降雨增加而导致的土壤化学-力学相互作用建模，以及（iii）不断变化的微观结构对土壤水力/强度特性的影响。(i)霜冻隆起和融化是造成季节性霜冻地区基础设施和地形（如泥石流）破坏的主要原因。本研究的主要目的是建立一个框架来描述原位冻土和含冰透镜的土壤的变形过程。该框架将用于模拟冻胀对油气管道完整性的影响。强烈降水往往导致土工结构的稳定性丧失，特别是粘性土壤中的天然斜坡和堤防的稳定性。这些土壤的性质是难以说明的，因为它涉及一个复杂的矿物学和化学因素系统。这里实施的方法将基于化学可塑性的框架。描述瞬态水-化学-力学耦合的控制方程将用于检验降雨作用下边坡的稳定性。* *再保险。（iii）环境荷载，即温度和降水，可以显著改变材料的微观结构，这往往导致宏观尺度上的各向异性。这项工作的主要目标将是引入材料织物的张量值描述符，为这些措施建立适当的演化规律，并将它们纳入宏观尺度框架。**研究结果将有助于基础知识和实际工程方面。****************