Theoretical and Experimental Solutions for Dynamic-Hydraulic-Mechanical Processes in Geoenvironmental Engineering

有效和可持续的解决方案，以应对全球地质环境挑战（如供水，能源生产，岩土工程基础设施的可持续性）需要对多孔介质中的颗粒输送有基本的了解。在地热、油气和含水层储采（ASR）系统运行过程中，固体颗粒在多孔介质中的沉淀和圈闭是导致孔隙堵塞的关键现象；影响水质和系统能力。相反，胶结和孔隙填充对岩土材料的工程性能有积极的影响；是生物介导的基础设施稳定背后的关键机制。对多孔介质中机械波与被困细颗粒之间物理相互作用的深入了解，对于开发突破性的增产策略至关重要，这些策略可以：(1)避免/减少/处理孔隙堵塞；(2)控制孔隙堵塞，增强农田尺度生物介导的土壤稳定。饱和介质中粒子输运和波传播的基本机制存在许多不确定性。此外，建立上述两种现象之间联系的实验尝试产生了不一致的结果；目前还没有耦合理论来解释波在含夹闭细粒的饱和介质中的传播。拟议研究计划的基本主题涉及多孔介质中的动态-水力-机械耦合，并着重于实质性地缩小这些关键的科学差距。我们提出了严格的理论建模和先进的物理实验，以实现三个具体目标：1)建立新的微观理论模型，以精确研究细颗粒的沉淀/动员/应变。2)建立新的波在饱和介质中传播的多尺度理论模型，探索波参数与区域微观结构和宏观尺度参数之间的耦合关系。最后，从新的基本认识出发，我们将发展新的理论来解释机械波与被困颗粒之间的首次物理相互作用。3)进行中试规模的实验室测试，以验证开发的模型，并评估波浪对物理/生物堵塞的形成和破裂的影响。因此，该研究项目将通过将振动刺激整合到注射策略中，为能源、水和生物稳定过程的设计增加一个新的维度。本研究建立的理论模型和实验模型不仅对科学知识的发展有重要的推动作用，而且对各种地质环境作业的实践也有重要的指导意义。所获得的解决方案可以防止井筒破裂造成的环境灾害以及土壤和水资源的污染。开发的战略还将使生物介导稳定技术的大规模实施成为可能，这主要是由于堵塞而受阻。

Efficient and sustainable solutions to global geoenvironmental challenges (e.g. water supply, energy generation, and geotechnical infrastructure sustainability) require a fundamental understanding of particle transport in porous media. The precipitation and entrapment of solid particles in porous media are crucial phenomena, resulting in pore blockage during the operation of geothermal, hydrocarbon, and aquifer storage and recovery (ASR) systems; impacting water quality and system competence. Conversely, cementation and pore-filling could have a positive effect on engineering properties of geomaterials; and are key mechanisms behind bio-mediated stabilization of infrastructure. The advanced understanding of physical interactions between mechanical waves and entrapped fine particles in porous media is critical for developing groundbreaking stimulation strategies to: (i) avoid/reduce/treat pore blockage; and (ii) control pore blockage to enhance field-scale bio-mediated soil stabilization. There are many uncertainties regarding fundamental mechanisms involved in particle transport, and wave propagation in saturated media. Furthermore, experimental attempts to establish the link between the aforementioned two phenomena have yielded inconsistent results; and there is currently no coupled theory to explain wave propagation in saturated media containing entrapped fines. The underlying theme of the proposed research program relates to dynamic-hydraulic-mechanical coupling in porous media, and focused on substantially closing these critical scientific gaps. We propose rigorous theoretical modeling and advanced physical experimentation, to achieve three specific goals: 1) develop new microscale theoretical models to enable accurate study of precipitation/mobilization/straining of fine particles. 2) Develop new multiscale theoretical models for wave propagation in saturated media, exploring coupled relations between wave parameters, the microstructure, and the macroscale parameters of the domain. Finally, from the new fundamental understandings, we will develop new theory to explain for the first-time physical interactions between mechanical waves and entrapped fines. 3) Conduct pilot-scale lab tests to verify the developed models, and to evaluate wave effects on formation and rupture of physical/biological clogging. Hence, this research program will add a new dimension to design of energy, water and bio-stabilization processes by integrating vibratory stimulation into injection strategies. The theoretical and experimental models obtained from this research will not only advance the scientific knowledge, but the state of practice in various geoenvironmental operations. The obtained solutions could prevent environmental disasters due to wellbore breakout and contamination of soil and water resources. Developed strategies will also enable large-scale implementation of bio-mediated stabilization techniques, which have been prevented mainly due to clogging.