Wave Loads and Structural Fragility Behind Impermeable and Permeable Obstacles

风暴和海啸造成的洪水对美国和世界各地的建筑物和基础设施造成了巨大破坏。 减少损害和总体风险缓解仍然是沿海社区现在和未来的优先事项，但这些目标在某些方面受到工程设计和分析工具的限制。 众所周知，在建筑物或植被后面，风暴波和海啸造成的破坏会减少，但事实证明，将这一常识转化为工程师和规划者的具体指导方针和标准是非常困难的。 该项目将使用理论、数值模型以及现场和实验室测量的结果来研究掩蔽结构后面的损害减少程度。这一分析的两个显著特点是，考虑到在一个事件期间遮蔽障碍物的退化，以及允许针对不同风险水平进行设计的概率分析框架。 有效地量化遮蔽结构物的荷载将消除洪水事件精确设计和规划的主要障碍。 该项目将有助于提高荷载估算的方式，将直接适用于许多工程设计的实例。与地震等灾害不同，来自风暴波或海啸的洪水事件（IE）荷载可以在O（10米）的尺度上变化，并受到周围自然和建筑环境的极大影响。 计算局部危险和局部载荷的不确定性仍然是确定规划和结构设计脆弱性的最大障碍：与裸土条件相比，障碍物后的载荷已被证明显着减少，但这些减少还不能量化为一般条件。 当考虑到一些障碍物可能是可渗透的流动（植被），或可能在IE的过程中降解，改变负载时，预测变得更加困难。 该项目将使用（1）缩放和理论分析;（2）计算流体动力学模拟;（3）结构分析;（4）现有的现场和实验室数据，研究位于单排障碍物后面的结构的IE危害强度，载荷和脆弱性。 分析将进一步考虑障碍退化的影响，使用障碍本身的脆弱性建模。结果将考虑使用代理建模，这将照亮在加载和脆弱性的不确定性的主要因素，并会建议通过哪些途径，结果可能会得到改善的不确定性。

Inundation from storm waves and tsunamis has caused great damage to buildings and infrastructure both in the United States and worldwide. Reduction of damage and overall risk mitigation remain priorities for coastal communities now and in the future, but these goals are in some ways limited by engineering design and analysis tools. Damage from storm waves and tsunamis is well known to be diminished behind structures or vegetation, but it has proven surprisingly difficult to translate this general knowledge to specific guidelines and standards for engineers and planners. This project will use theory, numerical models, and results from field and laboratory measurements to investigate the degree of damage reduction behind sheltering structures. Two notable features of this analysis will be the consideration of sheltering obstacle degradation during an event, and a framework for probabilistic analysis that will allow design for different levels of risk. Useful quantification of loading for sheltered structures will remove a major impediment to accurate design and planning for inundation events. This project will help to improve load estimates in ways that will be directly applicable to many instances of engineering design.Unlike hazards such as earthquakes, Inundation Event (IE) loading from storm waves or tsunamis can vary on scales of O(10m), and is greatly affected by the surrounding natural and built environments. Uncertainty in computing the local hazard and local loading remains the greatest obstacle in determining fragility for planning and structural design: Loads behind obstacles have been shown to decrease significantly when compared those from bare-earth conditions, but these decreases cannot yet be quantified for general conditions. Prediction becomes even more difficult when considering that some obstacles may be permeable to flow (vegetation), or may degrade over the course of the IE, changing loading. This project will examine IE hazard intensities, loading, and fragility for structures located behind a single row of obstacles using (1) Scaling and theoretical analyses; (2) Computational fluid dynamics simulations; (3) Structural analyses; (4) Existing field and laboratory data. Analyses will further consider the effects of obstacle degradation using fragility modeling of the obstacle itself. Results will consider uncertainties using surrogate modeling, which will both illuminate the major factors in loading and fragility uncertainties, and will suggest avenues through which results might be improved.