Risk Assessment of Bridges under Multihazard Effect of Earthquake and Flood-Induced Scour

地震发生在洪水引起的冲刷的存在是一个关键的多灾害的情况下，桥梁位于地震活跃的洪水易发地区。 本研究的目的是研究这种多灾害场景对桥梁设计的影响。 将制定一个分析多灾害框架，以评估位于美国三个地震活跃，洪水易发地区的代表性桥梁的可靠性，并量化地震和冲刷的综合影响下与这些桥梁相关的风险。 将开发区域洪水危险性曲线，并将这些危险性曲线与区域地震危险性相结合，描述桥梁的多危险情景。 根据开发的洪水风险曲线计算的桥梁冲刷将纳入有限元分析。 将进行可靠性分析，以评估由于各种分析模块中涉及的不确定性而导致的桥梁性能的可变性。结果将以（一）脆弱性表面和曲线以及（二）不同的多种灾害情景的风险曲线的形式呈现。 多灾害分析框架将被用来调查在洪水引起的冲刷存在的地震下的桥梁的几个抗震加固技术的有效性。 在完成这项研究后，该专业将获得一个全面的知识基础上的桥梁性能下的地震和洪水引起的冲刷的多重灾害的影响。 研究结果可进一步用于研究区域内桥梁的损失估计和未来事件下公路交通网络的性能评估。 本研究的目的是教育研究生和本科生的多个阶段的多灾害风险评估。将开发几个在线模块，使教育工作者，国家交通部和执业工程师利用研究成果为各自的目的。

The occurrence of earthquakes in the presence of flood-induced scour is a critical multi-hazard scenario for bridges located in seismically-active flood-prone regions. The objective of this research is to study the impact of this multi-hazard scenario on the design of bridges. An analytical multi-hazard framework will be formulated to assess the reliability of representative bridges located in three seismically-active, flood-prone regions of US and to quantify risk associated with these bridges under the combined effect of earthquake and scour. Regional flood hazard curves will be developed and multi-hazard scenario for bridges will be characterized by combining these hazard curves with regional seismic hazards. Bridge scour calculated from developed flood hazard curves will be incorporated in finite element analyses. Reliability analysis will be performed to assess the variability of bridge performance due to uncertainties involved in various analysis modules. Results will be presented in forms of (i) fragility surfaces and curves and (ii) risk curves for different multi-hazard scenarios. The multi-hazard analysis framework will be used to investigate the effectiveness of several seismic retrofit techniques for bridges under earthquakes in the presence of flood-induced scour. On completion of this research, the profession will have access to a comprehensive knowledge-base on bridge performance under multi-hazard effect of seismic and flood-induced scour. Results can be utilized further for loss estimation of bridges located in the study regions and for performance evaluation of highway transportation networks under future events. This research is designed to educate graduate and undergraduate students on multiple phases of multi-hazard risk assessment. Several online modules will be developed which will enable educators, state DOTs and practicing engineers to utilize the research outcome for their respective purposes.