Seismic Fragility Analysis for Typical Multi-Span Simply Supported Railway Box Girder Bridges

2016 ◽  
Vol 858 ◽  
pp. 137-144 ◽  
Author(s):  
Yun Dan Wu ◽  
Xiao Yao ◽  
Shi Jun Zhou
Keyword(s):  
Fragility Curves ◽  
Eastern China ◽  
Time History ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Simply Supported ◽  
Girder Bridges ◽  
Demand Models ◽  
Concrete Box Girder Bridges ◽  
Bridge System

Fragility curves for typical multi-span simply supported concrete box girder bridges in eastern China are presented. A set of bridge samples, of which five uncertain parameters are considered, is established using the Latin hypercube sampling. Nonlinear time history analyses are conducted to capture the structural response quantities. Probabilistic seismic demand models are formulated by quadratic regression analysis for the capacity/demand ratios. Fragility curves of bridge components are developed and the fragility of bridge system is evaluated using the first-order bound method. The results show that the columns and expansion bearings among bridge members are more fragile under earthquake excitation, and the bridge system is more fragile than any bridge component. The typical bridges have more than 50% probability when subjected to PGAs of 0.46, 0.58, 0.82, and 1.0g for four damage states, respectively. The fragility curves can be used for retrofit prioritization for this type of bridges.

Time-Dependent Seismic Fragilities of Older and Newly Designed Multi-Frame Reinforced Concrete Box-Girder Bridges in California

2019 ◽  
Vol 35 (1) ◽  
pp. 233-266 ◽  
Author(s):  
Mohammad Abbasi ◽  
Mohamed A. Moustafa
Keyword(s):  
Reinforced Concrete ◽  
Fragility Curves ◽  
Concrete Bridges ◽  
Time Dependent ◽  
System Level ◽  
Confidence Bounds ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Concrete Box Girder Bridges

Multi-frame box-girder reinforced concrete bridge is a common bridge class in California, characterized by the use of in-span hinges, which can have adverse effects, such as the pounding of adjacent frames and deck unseating during earthquakes. The goal of this study is to develop and compare a time-dependent overall system and individual components’ fragility curves of older and newly designed multi-frame reinforced concrete bridges in California. These are designed based on the pre-1971 and post-1994 seismic design specifications, respectively. Confidence bounds were developed to investigate the variability in the developed fragility curves. The study shows that older bridges have higher fragilities than new bridges at the system level, and the overall bridge system fragilities are less affected by time-dependent corrosion compared to the column fragilities. Moreover, the developed fragilities were compared to what is available in HAZUS for a better assessment of the currently available tools for this bridge type.

Probabilistic Performance Assessment of Retrofitted Horizontally Curved Multi-Frame RC Box-Girder Bridges

2017 ◽  
Vol 11 (04) ◽  
pp. 1750010 ◽  
Author(s):  
Hossein Pahlavan ◽  
Behzad Zakeri ◽  
Gholamreza Ghodrati Amiri
Keyword(s):  
Bridge Deck ◽  
Fragility Curves ◽  
Time History ◽  
Damage State ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Horizontally Curved ◽  
Girder Bridges ◽  
Damage States ◽  
Nonlinear Time History

Bridge horizontal deck curvature and the prevalence of in-span hinges in multi-frame RC box-girder bridges have reinforced this class of bridge to response with unique dynamic behavior during seismic excitations. This paper assesses the impacts of 10 different retrofit strategies on the vulnerability of curved multi-frame RC box-girder bridges with multi-column bents based on nonlinear time history analyses in OpenSEES. Consistent with HAZUS-MH definitions, fragility curves corresponding to four damage states at the component and system levels are developed for various bridge deck radii. The results indicate that combinations of retrofit strategies should be used to enhance the desirable level of bridge performance. Moreover, the most effective retrofit strategy in reducing probable damage for a given intensity is dependent on the bridge deck radius and is a function of the damage state of interest.

Adjustment Factors to Account for the Effect of Bridge Deck Horizontal Curvature on the Seismic Response of Concrete Box-Girder Bridges in California

2018 ◽  
Vol 34 (2) ◽  
pp. 893-914 ◽  
Author(s):  
Sujith Mangalathu ◽  
Jong-Su Jeon
Keyword(s):  
Bridge Deck ◽  
Fragility Curves ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Adjustment Factors ◽  
Concrete Box Girder ◽  
Concrete Box Girder Bridges ◽  
Horizontal Curvature ◽  
Different Levels

This research suggests adjustment factors to account for the effect of bridge deck horizontal curvature on the probabilistic seismic demand model (PSDMs) and fragility curves of concrete box-girder bridges in California. For this purpose, typical configurations of horizontally curved bridges in California are selected to create detailed three-dimensional (3-D) probabilistic bridge models with different levels of bridge deck horizontal curvature. Simulation results from the nonlinear time history analysis (NLTHA) of bridges are used to compare the PSDM of individual bridge components using a statistical technique called analysis of covariance (ANCOVA). Comparison results are used to group bridge classes and to suggest adjustment factors. Grouping results indicate that the PSDMs of unseating and bearing displacement are statistically significant for bridges with different levels of deck horizontal curvature. The effect of deck curvature and the use of the modification factors are demonstrated in this paper through the generation of fragility curves.

Crack-based serviceability assessment of post-tensioned segmental concrete box-girder bridges

Structures ◽  
2021 ◽  
Vol 30 ◽  
pp. 1097-1108
Author(s):  
Zhi-Qi He ◽  
Yonghui Li ◽  
Tian Xu ◽  
Zhao Liu ◽  
Zhongguo John Ma
Keyword(s):  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Concrete Box Girder ◽  
Concrete Box Girder Bridges ◽  
Post Tensioned

Study on Crack Causes and Strengthening Measures of Large Span PC Continuous Box Girder Bridges

2010 ◽  
Vol 163-167 ◽  
pp. 3551-3554
Author(s):  
Wei Peng ◽  
Zhi Xiang Zha
Keyword(s):  
Prestressed Concrete ◽  
Load Test ◽  
Box Girder Bridges ◽  
Element Analysis ◽  
Box Girder ◽  
Girder Bridges ◽  
Long Span ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge ◽  
Engineering Projects

This template Based on cracks observation and finite element analysis of real engineering projects as well as bridge load test after reinforcement, causes and types of cracks in prestressed concrete box girder bridges and treating measurements are systematically studied. The results obtained from the calculation are presented to demonstrate the effect of sensitive factors, such as arrangement of longitudinal prestressed tendons, the magnitude of vertical prestressed force, temperature gradient, etc. The results show that the arrangement of longitudinal prestressed tendons and the magnitude of vertical prestressed force take key roles in cracks control of box girder webs. Lots of treating measurements are presented in accordance with different types of cracks, some of them are applied to a reinforcement engineering of a long span pretressed concrete continuous box girder bridge with cracks. Load test after reinforcement of the bridge demonstrates the reasonability of the treating measurements. Several design recommendations and construction measures about reinforcements and some sensitive factors mentioned above are proposed to control cracks.

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