Seismic assessment of a multi-span steel railway bridge in Turkey based on nonlinear time history

Abstract

Abstract. Many research studies have shown that bridges are vulnerable to earthquakes, graphically confirmed by incidents such as the San Fernando (1971 USA), Northridge (1994 USA), Great Hanshin (1995 Japan), and Chi-Chi (1999 Taiwan) earthquakes, amongst many others. The studies show that fragility curves are useful tools for bridge seismic risk assessments, which can be generated empirically or analytically. Empirical fragility curves can be generated where damage reports from past earthquakes are available, but otherwise, analytical fragility curves can be generated from structural seismic response analysis. Earthquake damage data in Turkey are very limited, hence this study employed an analytical method to generate fragility curves for the Alasehir bridge. The Alasehir bridge is part of the Manisa-Uşak-Dumlupınar-Afyon railway line, which is very important for human and freight transportation, and since most of the country is seismically active, it is essential to assess the bridge's vulnerability. The bridge consists of six 30 m truss spans with a total span 189 m supported by 2 abutments and 5 truss piers, 12.5, 19, 26, 33, and 40 m. Sap2000 software was used to model the Alasehir bridge, which was refined using field measurements, and the effect of 60 selected real earthquake data analyzed using the refined model, considering material and geometry nonlinearity. Thus, the seismic behavior of Alasehir railway bridge was determined and truss pier reaction and displacements were used to determine its seismic performance. Different intensity measures were compared for efficiency, practicality, and sufficiency and their component and system fragility curves derived.

Preface: Damage of natural hazards: assessment and mitigation

“…Increasingly, aspects of social justice and equity are included in risk assessments to support the selection of optimal damage mitigation measures (Thaler et al, 2018). Two studies included in this special issue underpin this aspect by highlighting the importance of comprehensive event and risk assessments as well as integrated approaches to investigate the interaction of physical and socio-economic processes (Zhang et al, 2017;Markantonis et al, 2018). Additionally, cost assessments may include costs of the recovery phase as households may face enormous difficulties in recovering from events, as shown by Markantonis et al (2018) in this special issue.…”

“…The results show that reduction of the window openings affected the structural behaviour of the mosque positively. Zhang et al (2017) analyse the ripple effects of indirect economic damage and spatial heterogeneity of both direct and indirect economic damage caused by a hypothetical earthquake in the region of Beijing, China. Spatial heterogeneity of damage is analysed at the scale of streets, villages and towns.…”

“…The special issue "Damage of natural hazards: assessment and mitigation" was inspired by the annual EGU session "Costs of Natural Hazards", which was organized in 2012 for the first time. This special issue presents 12 studies on advancements in the field of damage assessment and mitigation related to droughts (Bachmair et al, 2017;Peichl et al, 2018;Markantonis et al, 2018), extreme rainfall (Cortès et al, 2018;Spekkers et al, 2017), different types of floods (Markantonis et al, 2018;Cortès et al, 2018;Laudan et al, 2017;Bernet et al, 2017;Wagenaar et al, 2017) and earthquakes (Livaoglu et al, 2018;Yılmaz et al, 2018;Altunışık et al, 2017;Zhang et al, 2017). A common challenge tackled by many of the studies in this special issue is the lack of impact and damage data.…”

Fragility analysis of a historical reinforced concrete arch railway bridge

“…Kumar and Gardoni [9] proposed probabilistic models to predict the effect of past earthquakes on the structural properties of RC highway bridge columns and their steel reinforcement, and then developed degradation models were used to assess the effects of seismic degradation on the seismic vulnerability of a RC highway bridge with one single-column bent. Yılmaz and Çağlayan [10] used both lateral displacement limit state and capacities of its structural members to derive fragility curves of a multi-span simply supported steel truss railway bridge. Pela et al [11] performed nonlinear static (pushover) analysis and nonlinear time history analyses for seismic capacity assessment of an existing brick masonry triple-arched bridge and showed that the pushover results can slightly overestimate the time-history average predictions.…”

Structural Evaluation of Railway Warren Steel Truss Bridge with Span Length of 42 Meter According to SNI 2833:2016 and Earthquake Hazard Map 2017

“…Other test was also conducted to see the vulnerability of the railway bridge [18], while structure damage detection is also proposed by its dynamic characters in other study [19]. Many other research related to steel truss bridges under seismic namely in Turkey [20] and for pedestrian bridges [21]. Beside the seismic load, the moving load also became a factor that give the vibration or dynamic activity in the bridge [22].…”