Development of Micromechanically-Based Models for Unsaturated Geomaterials

与基础设施、能源和环境相关的新出现的地质力学问题对岩土工程的基本原理提出了挑战。例如，非饱和、热和耦合条件需要超越传统理论的分析，而传统理论大多是现象学的。在最简单的情况下，不饱和指的是存在一种以上的流体，例如在孔隙空间内被界面隔开的液体和气体。这导致非饱和介质的行为与干燥或完全饱和的情况有很大的不同。事实上，非饱和度赋予介质明显的内聚力，即更高的强度和硬度，这是水分和温度的函数。这种强度的增加在不同的水力和热负荷下是短暂的，例如气候波动或充气条件。因此，强度可能会迅速丧失，从而导致地质结构的自发性坍塌。

Emerging geomechanics problems associated with infrastructure, energy and the environment present challenges to basic tenets of geotechnical engineering. For instance, unsaturated, thermal and coupled conditions demand analyses that go beyond traditional theories which are mostly phenomenological in nature. Unsaturation in the simplest case refers to the presence of more than one fluid, e.g. liquid and gas separated by interfaces within the pore space. This results in the behaviour of an unsaturated medium being vastly different from the dry or fully saturated case. In fact, unsaturation confers the medium with an apparent cohesion, a higher strength and stiffness that are a function of moisture and temperature. This gain in strength is evanescent under varying hydraulic and thermal loads such as climatic fluctuations or gassy conditions. As such, strength could be rapidly lost causing spontaneous collapse failures in geostructures.