Novel numerical and experimental methods for efficient assessment of the structural safety and rehabilitation strategies of dams and water-structure systems

本研究计划提出新的数值和实验方法，以有效评估水坝和水结构系统的结构安全性和修复策略。大坝和水构筑物的破坏可能导致灾难性的后果，由于水的释放而远远超出了受损结构的邻近地区。这些结构大多已经服役超过50年，它们最初的设计可能无法满足现代安全标准。这项工作将侧重于开发可靠的2D/3D数值工具，以有效和严格地模拟冰盖对混凝土大坝地震和洪水安全的影响。将使用有限元（FE）和计算流体动力学（CFD）方法。将提供准则和说明性案例研究目录，说明在北部气候条件下的大坝地震和洪水安全评估中纳入冰盖影响的重要性。可靠、准确的水动压力预测对于大坝、闸门、储罐、进水塔、船闸等与水接触的振动结构的地震安全性评价至关重要。这些结构中的大多数都是震后关键的生命线系统，以及电力和水的分配网络。本研究的部分目的是开发新的简化而严格的方法来实际评估水结构体系的地震易损性。所提出的方法将考虑水的可压缩性、流体域边界处的能量耗散、基础灵活性、冰盖和三维效应。这些方法将在计算机应用程序中编程，并以适合优化设计和快速地震脆弱性筛选的格式实施。最后，本提案将解决新的振动台测试程序，用于研究受水库，冰和地震载荷影响的大型新建和修复混凝土大坝。将开发一个原始的附加质量系统来解释大型重力坝样本的静力、水动力和冰荷载，并用于实验评估重力坝的非线性响应，识别破坏模式和验证数值预测模型。

This research program proposes novel numerical and experimental methods for efficient assessment of the structural safety and rehabilitation strategies of dams and water-structure systems. Dam and water-structure failures may lead to catastrophic consequences, extending far beyond the immediate neighbourhood of the damaged structure due to water release. Most of these structures have been in service over 50 years, and their initial design may fail to meet modern safety criteria. This work will focus on developing reliable 2D/3D numerical tools to effectively and rigorously simulate ice cover effects on the seismic and flood safety of concrete dams. Finite Element (FE) and Computational Fluid Dynamic (CFD) Methods will be used. Guidelines and a catalogue of illustrative case studies on the significance of including ice cover effects in the seismic and flood safety assessment of dams in northern climates will be provided. Reliable and accurate prediction of hydrodynamic pressure is of uppermost importance to the seismic safety evaluation of structures vibrating in contact with water including dams, gates, storage tanks, intake towers, and navigation locks. Most of these structures are critical post-earthquake lifeline systems along with electric and water distribution networks. Part of this research aims at developing novel simplified and yet rigorous methods for practical assessment of the seismic vulnerability of water-structure systems. The proposed methods will account for water compressibility, energy dissipation at the fluid domain boundaries, foundation flexibility, ice cover and 3D effects. The methods will be programmed in computer applications and implemented in a format amenable to optimized design and rapid seismic vulnerability screening. Finally, this proposal will address novel shake table testing procedures for studying large scale new and rehabilitated concrete dams subjected to reservoir, ice and seismic loadings. An original added-mass system to account for static, hydrodynamic and ice loads on large scale gravity dam specimens will be developed and used to experimentally assess the nonlinear response of gravity dams, identify failure modes and validate the numerical predictive models.