Probabilistic performance assessment of low-ductility reinforced concrete frames retrofitted with dissipative braces
Probabilistic performance assessment of low-ductility reinforced concrete frames retrofitted with dissipative braces
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DOI：
10.1002/eqe.2255
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发表时间：
2013-06-01
影响因子：
4.5
通讯作者：
Dall'Asta, A.
中科院分区：
文献类型：
--
作者：
Freddi, F.;Tubaldi, E.;Dall'Asta, A.
本文阐述了一种概率方法，用于评估现有有限延性能力的钢筋混凝土（RC）建筑物的易损性，通过耗散支撑进行改造。目的是强调控制这些耦合系统的能力的最重要的参数和有关响应不确定性的具体方面。所提出的方法是基于使用当地工程需求参数来监测地震反应，以及在改造前后组件和系统脆弱性曲线的发展。在本文的第一部分中，通过突出其相对于现有方法的优势来说明该方法。然后，通过一个仅为重力荷载设计的基准二维RC框架，对其性能和有效性进行了测试。框架是通过引入弹塑性耗散支撑设计不同水平的基础剪切能力进行改造。所获得的结果表明，该方法在描述不同改造水平的改造前后响应和失效模式的变化方面是有效的。此外，通过引入描述易损性曲线的适当综合参数，并强调在由低延性RC框架和耗散支撑组成的耦合系统的地震风险评估中使用局部工程需求参数（EDPs）而不是全局工程需求参数的重要性，对改造效果进行了评估。版权所有：John Wiley & Sons， Ltd。
The paper illustrates a probabilistic methodology for assessing the vulnerability of existing reinforced concrete (RC) buildings with limited ductility capacity retrofitted by means of dissipative braces. The aim is to highlight the most important parameters controlling the capacity of these coupled systems and specific aspects concerning the response uncertainties. The proposed methodology is based on the use of local engineering demand parameters for monitoring the seismic response and on the development of component and system fragility curves before and after the retrofit. In the first part of the paper, the methodology is illustrated by highlighting its advantages with respect to the existing approaches. Then, its capability and effectiveness are tested by considering a benchmark two-dimensional RC frame designed for gravity-loads only. The frame is retrofitted by introducing elasto-plastic dissipative braces designed for different levels of base shear capacity. The obtained results show the effectiveness of the methodology in describing the changes in the response and in the failure modalities before and after the retrofit, for different retrofit levels. Moreover, the retrofit effectiveness is evaluated by introducing proper synthetic parameters describing the fragility curves and by stressing the importance of employing local engineering demand parameters (EDPs) rather than global EDPs in the seismic risk evaluation of coupled systems consisting in low-ductility RC frames and dissipative braces. Copyright (c) 2012 John Wiley & Sons, Ltd.