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

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.

2017 ◽  
Vol 22 (5) ◽  
pp. 881-901 ◽  
Author(s):  
Reihaneh Sarraf Shirazi ◽  
Gokhan Pekcan ◽  
Ahmad Itani

2016 ◽  
Vol 858 ◽  
pp. 137-144 ◽  
Author(s):  
Yun Dan Wu ◽  
Xiao Yao ◽  
Shi Jun Zhou

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.


2018 ◽  
Vol 34 (2) ◽  
pp. 893-914 ◽  
Author(s):  
Sujith Mangalathu ◽  
Jong-Su Jeon

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.


1998 ◽  
Vol 68 (5) ◽  
pp. 513-528 ◽  
Author(s):  
Dongzhou Huang ◽  
Ton-Lo Wang ◽  
M. Shahawy

2011 ◽  
Vol 94-96 ◽  
pp. 326-331
Author(s):  
Jun He ◽  
Bin Han ◽  
Yu Qing Liu ◽  
Ai Rong Chen

Horizontally curved box girder bridges inherently exhibit complex torsional and distortional behavior as well as bending due to the initial curvature. As to the horizontal curved composite box-girder bridges with corrugated webs, diaphragms were arranged reasonably to reduce torsional and distortion effect for safety and stability due to the coupling of bending and torsion effect for initial curvature and reduced bending stiffness in horizontal direction for corrugated steel webs. Finite element models for a 3-spans continuous horizontal curved composite box girder bridges with corrugated webs were established. Comparing the ratio of warping normal stress to bending normal stress, the influence of the number and spacing for diaphragms on distortion control for curved bridges is investigated. Extensive parametric studies (including central angle, the aspect ratio of the box section, the spacing of the intermediate diaphragms)are performed and the design suggestions for the maximum spacing of the intermediate diaphragms are presented.


1995 ◽  
Vol 22 (1) ◽  
pp. 93-105 ◽  
Author(s):  
M. S. Cheung ◽  
S. H. C. Foo

Because of their excellent torsional capacity, box girders are used extensively in modern bridge construction having curved alignments. Applications of most design codes have been limited to bridges where the radius of curvature is much greater than the span length and cross-sectional dimensions. To meet the practical requirements arising during the design process, simple design methods are needed for curved bridges. This paper presents the results of a parametric study on the relative behaviour of curved and straight box-girder bridges and on the development of a simplified design method for the combined longitudinal moment of curved bridges. The combined moment includes the effects of flexure, torsion, and distortion. Three simply supported concrete-steel composite bridge models, including single-cell, twin-cell, and three-cell box girders and subjected to loadings as specified in the Ontario Highway Bridge Design Code, were analyzed using the finite strip method. The parameters considered in the study include types of cross section; types, locations, and magnitudes of loads; span lengths; and radius of curvature. Preliminary analysis of the results suggests that the behaviour of horizontally curved box-girder bridges is dependent on a variety of parameters, but most importantly on the span-to-radius ratio. Empirical relationships for combined longitudinal moment between curved and straight box-girder bridges are also proposed. Key words: bridge, curved, composite, design, finite strip.


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