Advanced thermo-hydro-mechanical interactions in underground structures

地下结构中先进的热-水-机械相互作用

• 批准号: 2244324
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2244324
• 关键词: Advanced; thermo; hydro; mechanical; interactions

This project aims at characterising the effect of thermo-hydro-mechanical interactions between different components of underground structures and the surrounding soil, and the subsequent impact on their design. Two sources of temperature changes are explored using a combination of 2D and 3D finite element modelling: the activation of structures using heat exchanger pipes and the hydration of concrete. Concerning the former, building upon work carried out by researchers on simplified modelling of thermo-active structures, such as retaining walls and pile foundations, this project will analyse the impact on the temperature fields across the pile section of modelling the thermal loading by explicitly simulating heat exchanger pipes. This will also enable a first-of-its-kind analysis of thermal fluxes in these structures, demonstrating where heat is being stored in different time-frames, as well as characterising the efficiency of such storage, providing further indication of these systems' capabilities as a providers of low-carbon heating and cooling to buildings. Lastly, it is expected that a simplified, yet accurate, modelling approach that yields estimates of pile forces due to temperature changes without the need for computational expensive 3D finite element analysis is produced in order to render their design more approachable by industry practitioners. The second heat source to be considered is the hydration of concrete. These structures are characterised by very large quantities of concrete poured into excavated cavities within the ground. Subsequent chemical reactions are extremely exothermic, producing large quantities of heat that flows from the structure into the ground, triggering a complex interaction mechanism which this project will analyse. A new practical model for simulating this process in geotechnical finite element analyses will be formulated and implemented into the bespoke code ICFEP. Temperature fields around underground structures will be characterised and, where possible, results will be compared to field data for validation purposes (e.g. temperature fields from thermal integrity testing). Lastly, implications from temperature fields generated during hydration to the safe operation of thermo-active structures will be investigated.

该项目旨在表征地下结构不同组成部分与周围土壤之间的热-水-机械相互作用的效果，以及随后对其设计的影响。温度变化的两个来源进行了探讨，使用二维和三维有限元建模相结合：激活结构使用热交换器管道和混凝土的水合作用。关于前者，在研究人员对热活性结构（如挡土墙和桩基）进行简化建模的基础上，该项目将分析通过明确模拟热交换器管道来模拟热负荷对整个桩段温度场的影响。这也将首次对这些结构中的热通量进行分析，展示在不同的时间范围内热量被储存在哪里，并表征这种储存的效率，进一步表明这些系统作为建筑物低碳供暖和制冷供应商的能力。最后，预计一个简化的，但准确的，建模方法，产生由于温度变化的桩力的估计，而不需要计算昂贵的三维有限元分析，以使他们的设计更接近行业从业者。第二个要考虑的热源是混凝土的水化。这些结构的特点是大量的混凝土浇注到地面内挖掘的洞穴中。随后的化学反应是非常放热的，产生大量的热量，从结构流入地下，引发了一个复杂的相互作用机制，本项目将分析。一个新的实用模型，用于模拟这一过程中的岩土有限元分析将制定和实施到定制的代码ICFEP。将对地下结构周围的温度场进行表征，并在可能的情况下，将结果与现场数据进行比较，以进行验证（例如，热完整性测试的温度场）。最后，将研究水化过程中产生的温度场对热活性结构安全运行的影响。