Modeling Effect of Molecular Interactions on Evolution of Microstructure and Swelling and Swelling Pressure Responses in Montmorillonite Expansive Clays

21世纪世纪工程研究人员利用强大的计算、实验和分析技术，将首次使岩土工程师和地质环境工程师能够模拟和理解极其复杂和重要的粘土膨胀现象。膨胀土的膨胀响应和膨胀受到抑制时相应的膨胀压力的发展是颗粒之间和颗粒本身内部复杂的粘土-水相互作用的结果。这些相互作用是膨胀性粘土膨胀行为的基础，对美国和世界各地的基础设施造成了巨大的破坏。这些基本分子相互作用的定量建模对于结构设计和开发解决方案以防止膨胀土的有害影响以及评估这些材料用于环境工程和其他工程应用的可行性至关重要。本研究的重点是模拟膨胀土中粘土颗粒间、粘土流体间以及夹层间的相互作用对膨胀特性的影响。该项目使用分析，计算和实验技术相结合，开发模型桥接分子水平的粘土-流体相互作用的宏观尺度响应的膨胀粘土使用分层多尺度建模方法。所使用的建模技术是分子动力学和离散元建模和实验工作使用振动显微光谱，原子力显微镜和X射线衍射。

AbstractThe powerful computational, experimental and analytical techniques available to engineering researchers in the 21st century will allow geotechnical and geoenvironmental engineers for the first time to model and understand the extremely complex and important phenomenon of swelling of clays. The swelling response of expansive clays and corresponding development of swelling pressure when swelling is restrained is a result of complex clay-water interactions between particles and within the particles themselves. These interactions are the basis of the swelling behavior in expansive clays that causes tremendous damage to infrastructure in the United States and around the world. The quantitative modeling of these fundamental molecular interactions are critical for design of structures and developing solutions to prevent the detrimental effects of swelling soil, as well as for evaluating the feasibility of use of these materials for environmental engineering and other engineering applications. The focus of this project is to model the influence of interactions of clay particle-particle and clay-fluid and interlayer on swelling characteristics in expansive clays. This project uses a combination of analytical, computational and experimental techniques to develop models bridging molecular level clay-fluid interactions to macroscale response of swelling clays using a hierarchical multiscale modeling approach. The modeling techniques used are molecular dynamics and discrete element modeling and the experimental work uses vibrational microspectroscopy, atomic force microscopy and X-ray diffraction.