Performance-based Multi-Hazard Engineering for Seismic and Wind Loads

基于性能的地震和风荷载多灾害工程

• 批准号: 1265511
• 负责人: Mircea Grigoriu
• 金额: $ 30万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1265511&HistoricalAwards=false
• 关键词: Performance; based; Multi; Hazard; Engineering

The overall objective of the project is to explore and advance the state-of-the-art in performance-based engineering in the context of multi-hazard analysis for earthquakes and windstorms. Performance-based engineering is a maturing concept requiring structures to meet specified objectives depending on the intensity of earthquake/windstorm loads. Practical implementation of this concept is not possible without the availability of efficient methods for quantifying the uncertainty in structural loads and propagating this uncertainty into response statistics. The last two decades have seen significant developments in both the quantification of load uncertainty and its propagation through structural systems. However, research is needed to describe earthquake/wind loads probabilistically, quantify material/structural uncertainties, and calculate response statistics. The proposed research will enhance preliminary work done by the Principal Investigator under a previous NSF grant.The project will address uncertainty quantification and propagation and integrate them in a practical methodology for multi-hazard analysis. Task 1 will develop novel probabilistic models for seismic/wind hazards and loads that are based on all available information and are capable of capturing with increased accuracy the essential features of these loads. Hazards and loads will be characterized probabilistically by two parameters: moment magnitude and source-to-site distance for seismic loads and speed and direction for wind loads. Task 2 will develop conceptually simple, accurate, non-intrusive, and computationally efficient methods for calculating response statistics, fragility and damage/cost/downtime probability distributions, for structural systems in the linear/nonlinear regime under Gaussian/non-Gaussian loads. The method is based on stochastic reduced order models, and can be viewed as a smart Monte Carlo simulation. Task 3 will use results from previous two tasks to implement a practical methodology for performance-based multi-hazard engineering for seismic and wind loads. The task will calculate probability distributions for damage, cost, downtime, robustness, recovery, and other performance/resilience metrics. Robustness and recovery characterize the ability of structural/non-structural systems to withstand extreme events with limited loss of function and the time needed to restore the functionality of these systems to their pre-event level. Probability distributions, rather than expectations, will be used since they provide refined tools for decision making.

该项目的总体目标是在地震和风暴多灾害分析的背景下，探索和推进基于性能的工程的最新技术。基于性能的工程是一个成熟的概念，要求结构满足特定的目标，这取决于地震/风暴荷载的强度。如果没有有效的方法来量化结构荷载的不确定性并将这种不确定性传播到响应统计中，这一概念的实际实施是不可能的。在过去的二十年中，在荷载不确定性的量化及其在结构系统中的传播方面取得了重大进展。然而，地震/风荷载的概率描述、材料/结构不确定性的量化以及响应统计量的计算都需要进行研究。拟议的研究将加强首席研究员在以前的NSF资助下所做的初步工作。该项目将处理不确定性的量化和传播，并将它们整合到多危害分析的实用方法中。任务1将基于所有可用信息开发地震/风灾害和载荷的新型概率模型，并能够以更高的精度捕获这些载荷的基本特征。灾害和荷载将由两个参数概率表征：地震荷载的矩级和震源到场地的距离，风荷载的速度和方向。任务2将开发概念上简单、准确、非侵入性和计算效率高的方法，用于计算高斯/非高斯载荷下线性/非线性结构系统的响应统计、易损性和损坏/成本/停机概率分布。该方法基于随机降阶模型，可以看作是一种智能蒙特卡罗模拟。任务3将使用前两项任务的结果来实现基于性能的地震和风荷载多灾害工程的实用方法。该任务将计算损坏、成本、停机时间、健壮性、恢复和其他性能/弹性指标的概率分布。鲁棒性和恢复性表征了结构/非结构系统承受极端事件的能力，其功能损失有限，并且需要将这些系统的功能恢复到事件前的水平。将使用概率分布，而不是期望，因为它们为决策提供了精细的工具。