Seismic fragility analysis of typical pre-1990 bridges due to near- and far-field ground motions

Abstract

Bridge damages during the past earthquakes caused several physical and economic impacts to transportation systems. Many of the existing bridges in earthquake prone areas are pre-1990 bridges and were designed with out of date regulation codes. The occurrences of strong motions in different parts of the world show every year the vulnerability of these structures. Nonlinear dynamic time history analyses were conducted to assess the seismic vulnerability of typical pre-1990 bridges. A family of existing concrete bridge representative of the most common bridges in the highway system in Iran is studied. The seismic demand consists in a set of far-field and nearfield strong motions to evaluate the likelihood of exceeding the seismic capacity of the mentioned bridges. The peak ground accelerations (PGAs) were scaled and applied incrementally to the 3D models to evaluate the seismic performance of the bridges. The superstructure was assumed to remain elastic and the nonlinear behavior in piers was modeled by assigning plastic hinges in columns. In this study the displacement ductility and the PGA are selected as a seismic performance indicator and intensity measure, respectively. The results show that pre-1990 bridges subjected to near-fault ground motions reach minor and moderate damage states. Keywords Concrete bridges Á Seismic vulnerability Á Time history analysis Á Fragility curves Á Far-field Á Near-fault & Araliya Mosleh

Development of fragility curves for RC bridges subjected to reverse and strike-slip seismic sources

“…Circular solid columns are considered for two major bridge classes. Based on the analysis of Iran bridge inventory, Mosleh (Mosleh 2016) found that most of the bridges in Iran have skew angles less than 5°, therefore the effect of skew angle is eliminated in this study (Mosleh et al 2016a). For each bridge class, different case studies are considered; Shinozuka et al (Shinozuka et al 2000) considered ten sample bridge classes, whereas six samples were analyzed by Choine et al (Choine et al 2015).…”

“…In the lack of adequate damage data or expert option, analytical fragility curves are the best choice to assess the seismic performance of highway bridges. The curves can be developed by a variety of analytical methods, such as elastic spectral method (Hwang 2000), nonlinear static analysis (Dutta and Mander 1998, Loh et al 2002, Monti and Nistico 2002, Banerjee and Shinozuka 2007, Siqueiraa et al 2014, nonlinear response history analysis (NLTHA) (Hwang et al 2001, Karim and Yamazaki 2003, Choi et al 2004, Elnashai et al 2004, Choine et al 2015, Ramanathana et al 2015, Yang et al 2015, Mosleh et al 2016a, Nateghi and Shahsavar 2004 and incremental dynamic analysis (IDA) (Billah et al 2013, Billah and Alam 2016, Dezfuli and Alam 2016. In the past decades, there have been significant researches regarding seismic vulnerability of buildings, however, less investigation has been devoted to bridges (Bojórquez et al 2012, Mollaioli et al 2013, Mosleh et al 2016b.…”

Fragility Analysis of a Self‐Anchored Suspension Bridge Based on Structural Health Monitoring Data

“…Parool and Rai [12] used the archetype model of a multispan simply supported bridge with drop spans and steel bearings to demonstrate the seismic vulnerability can be significantly reduced in such bridges if the steel bearings are replaced with elastomeric pads. Mosleh et al [13] generated fragility curves for one of the most common bridge typologies, to investigate the seismic performance of RC bridges built before the 1990s. In addition, some studies have focused on the seismic fragility of cable-stayed bridges using the analytical method.…”

Improved semi-active control algorithm for hydraulic damper-based braced buildings

“…As a result, the buildings usually have to behave with substantial damage and possibly permanent deformation. Currently, major earthquakes, such as Sichuan earthquake in China (2008), Christchurch earthquake in New Zealand (2011), Chile earthquake (2010), and Great Sendai earthquake in Japan (2011) confirm this big concern of modern seismic design concept for resilience of buildings and bridges …”

“…Currently, major earthquakes, such as Sichuan earthquake in China (2008), Christchurch earthquake in New Zealand (2011), Chile earthquake (2010), and Great Sendai earthquake in Japan (2011) confirm this big concern of modern seismic design concept for resilience of buildings and bridges. [4][5][6][7] Research on innovative designs and materials for new and existing buildings has demonstrated their enhanced seismic performance. [8,9] These design approaches mainly include (a) using base isolation concepts or devices to control and reduce the demand, [10,11] (b) using shape memory alloy, [12,13] expansion concrete [14] or post-tensioning active confinement [15] to minimize or eliminate permanent deformation, and (c) using jacketing [16,17] through passive confinement to increase ductility capacity.…”