Abstract

A prominent challenge in performance-based earthquake engineering is to select a suitable set of ground motions records with which to perform probabilistic seismic assessment of structures. The most common approach for engineering purposes is to employ actual recordings of worldwide events, given that large earthquakes do not occur frequently hence regional recordings of such events are usually not widely available. To address this not that uncommon issue, regionally simulated ground motions using a stochastic finite-fault method have been proposed as an alternative to real records. This study aims to explore the use of simulated records through a stochastic finite-fault method in probabilistic seismic assessment frameworks for reinforced concrete bridges, when compared to using real records. Direct seismic losses for a case-study existing bridge and a bridge portfolio are estimated and compared, as the reference risk metric. Finally, the similarities between seismic demands, obtained using both real and simulated record sets, are quantified and discussed via statistical hypothesis testing, resulting fragility curves and expected annual losses. The results show how simulated records can be a promising alternative to real records, becoming particularly useful in the absence of available recorded ground motions with specific seismogenic features.

摘要

基于性能的地震工程的一个突出挑战是选择一组合适的地面运动记录来执行结构的概率地震评估。出于工程目的，最常见的方法是采用世界范围内事件的实际记录，因为大地震不会经常发生，因此此类事件的区域记录通常无法广泛获得。为了解决这个并不少见的问题，已经提出使用随机有限断层法的区域模拟地面运动作为真实记录的替代方法。与使用真实记录相比，本研究旨在通过随机有限断层法探索模拟记录在钢筋混凝土桥梁概率地震评估框架中的使用。对现有桥梁案例研究和桥梁组合的直接地震损失进行估计和比较，作为参考风险度量。最后，使用真实和模拟记录集获得的地震需求之间的相似性通过统计假设检验、由此产生的脆弱性曲线和预期年损失进行量化和讨论。结果表明，模拟记录如何成为真实记录的有前途的替代品，在没有具有特定地震特征的可用记录地面运动的情况下变得特别有用。由此产生的脆弱性曲线和预期的年度损失。结果表明，模拟记录如何成为真实记录的有前途的替代品，在没有具有特定地震特征的可用记录地面运动的情况下变得特别有用。由此产生的脆弱性曲线和预期的年度损失。结果表明，模拟记录如何成为真实记录的有前途的替代品，在没有具有特定地震特征的可用记录地面运动的情况下变得特别有用。