Abstract

The rigid-frame bridges with a fully continuous moment connection between the superstructure and substructure piers are suitable for high-seismic regions; however, research on the response of these bridge types under tsunami loads is limited. This paper presents a framework for developing fragility functions of coastal rigid-frame bridges, and bridges with strong pier-to-deck connectivity, undergoing tsunami-induced hydrodynamic loads. The fragility analysis is demonstrated on a three-span reinforced concrete (RC) bridge structure with double-column bents. The Monte Carlo simulation is implemented to consider the uncertainties in capacity and demand parameters. The efficiency of single-parameter and two-parameter intensity measures for predicting the response of bridges is examined. The viability of strengthening bridge piers using fiber-reinforced polymer (FRP) is also investigated. The results indicate that the use of two-parameter intensity measures is a better option to estimate the structural response since the hydrodynamic forces are a function of both the flow depth and velocity. This also leads to a significant reduction in the scatter of fragility data. The comparative assessment of the initial and FRP-strengthened bridges highlights that the FRP-jacketing is an effective method in reducing the risk of failure of the rigid-frame bridges.

摘要

上部结构和下部结构桥墩之间具有完全连续弯矩连接的刚架桥适用于高地震区；然而，对这些桥梁类型在海啸载荷下的响应的研究是有限的。本文提出了一个开发沿海刚架桥梁的脆弱性功能的框架，以及具有强大的码头到甲板连接性的桥梁，承受海啸引起的水动力载荷。脆弱性分析是在具有双柱弯曲的三跨钢筋混凝土 (RC) 桥梁结构上进行的。实施蒙特卡罗模拟以考虑容量和需求参数的不确定性。检验了预测桥梁响应的单参数和双参数强度测量的效率。还研究了使用纤维增强聚合物 (FRP) 加固桥墩的可行性。结果表明，使用双参数强度测量是估计结构响应的更好选择，因为水动力是流动深度和速度的函数。这也导致脆弱性数据的分散显着减少。对初始桥梁和 FRP 加固桥梁的比较评估表明，FRP 护套是降低刚架桥梁失效风险的有效方法。这也导致脆弱性数据的分散显着减少。对初始桥梁和 FRP 加固桥梁的比较评估表明，FRP 护套是降低刚架桥梁失效风险的有效方法。这也导致脆弱性数据的分散显着减少。对初始桥梁和 FRP 加固桥梁的比较评估表明，FRP 护套是降低刚架桥梁失效风险的有效方法。