Multiphysics of Fluid-Saturated Geomaterials and Chemically Damaged Barriers

*这项研究将开发岩土材料耦合过程的创新实验技术和理论模型，并在计算方案中实施这些方法，以检查和预测对能源回收、核废料管理、温室气体地质封存和地热能源开采至关重要的地质处置和遏制战略的结果。需要在热(T)、水力(H)、机械(M)和化学(C)过程相互作用的背景下理解多物理耦合的作用。该研究计划的重点是在理论、计算和实验程序方面取得必要的进展，这些程序可以立即应用于地质环境保护战略。*核废物管理组织的目标是用于放射性废物深层地质储存的高度不均匀的Cobourg石灰岩，将使用大圆柱形样品(直径150 mm，长300 mm)进行研究。岩石的内部特征在多尺度耦合过程方面是一个挑战，因此，将使用最近获得的具有声发射层析成像功能的三轴单元进行实验，以逐步跟踪将影响THM响应的缺陷演变。这种设备是加拿大独有的。利用实验结果，将获得可靠的Cobourg石灰石THM行为模型，以预测NWMO倡议的长期情景。*这项研究还将检查THMC在碳酸盐岩储层中二氧化碳地质储存方面的影响，因为加拿大的目标储存层主要是碳酸盐岩。初步研究表明，在富含碳酸盐的样品中，虫洞或溶解通道迅速发育；这将影响含水层的储存潜力，并损害为盖层屏障提供稳定性的结构支撑。将对来自威伯恩、SK、Brooks、AB和Béancour，QC的储存岩进行测试，并开发模型，将裂缝和封闭面的化学侵蚀与地应力状态和碳酸盐含量的变化联系起来。*研究还将探讨化学物质在土工合成材料力学中的作用，特别是由于去除增塑剂而导致的脆化，并研究化学物质在土工膜中的应力辅助传输导致的各向异性效应。将开发对速率敏感的本构模型；这些模型可用于预测缺陷处、连接接缝处的撕裂失效，特别是乙醇等化学物质的局部作用区域。*未来五年，该研究计划将培养PDF、博士、硕士和UG学生，掌握有效为这些领域做出贡献的技能。这些项目将对环境保护政策的制定产生重大影响。**

*This research will develop innovative experimental techniques and theoretical models of coupled processes in geomaterials and implement the approaches in computational schemes that can examine and predict the outcome of geologic disposal and containment strategies important to energy resources recovery, nuclear waste management, geologic sequestration of greenhouse gases and geothermal energy extraction. The role of multiphysics couplings needs to be understood in the context of the interaction of thermal (T), hydraulic (H), mechanical (M) and chemical (C) processes. The emphasis of the research program is to achieve the necessary advances in theoretical, computational and experimental procedures that have immediate applications to geoenvironmental protection strategies. ***The highly heterogeneous Cobourg Limestone, targeted by the Nuclear Waste Management Organization, ON, for deep geological storage of radioactive wastes, will be studied using large cylindrical samples (150 mm dia., 300 mm long). The internal features of the rock present a challenge in terms of multi-scale coupled processes and for this reason, experiments will be performed using the recently acquired Triaxial Cell with Acoustic Emission Tomography mapping capabilities, to progressively track defect evolution that will affect the THM responses. This equipment is unique to Canada. Using the experimental results, reliable models of the THM behaviour of Cobourg Limestone will be achieved to predict the long-term scenarios of NWMO initiatives. ***The research will also examine THMC effects in geologic storage of CO2 in carbonate reservoirs since the targeted storage horizons in Canada are largely carbonate rocks. Preliminary studies reveal that wormholes or dissolution channels develop rapidly in carbonate-rich samples; this will affect the storage potential of the aquifer and compromise the structural support that provides stability for caprock barriers. Storage rocks from Weyburn, SK, Brooks, AB and Bécancour, QC will be tested and models developed to relate chemical erosion at fractures and sealing interfaces to alterations in geostatic stress states and carbonate content. ***Research will also address the role of chemicals on the mechanics of geosynthetics, particularly their embrittlement due to plasticizer removal, and examine the stress-assisted transport of chemicals in geomembranes leading to anisotropic effects. Rate-sensitive constitutive models will be developed; these could be used to predict tearing failure at defects, at connecting seams and, in particular, the localized regions of action of chemicals such as ethanol. ***Over the next five years, the research program will train PDFs, PhDs, Masters and UG students, with skills to effectively contribute to these areas. The projects will have a significant impact on the development of policy for the protection of the environment. **