Estimation of Structural Safety for Internally Grouted Post-tensioned External Tendons

Author(s):  
Yeun Chul Park ◽  
Ho-Kyung Kim ◽  
Chul-Hwan Yoo ◽  
Suk-Hee Bong

In February, 2016, one of the external tendons in pre‐stressed concrete (PSC) box girder bridge in Seoul was failed due to corrosion after 17 years of service. The failure was found during the thawing season regular inspection. Since it was the first tendon failure occurred in South Korea, in‐depth investigation was performed and found that multiple tendons were corroded at many different locations. Seoul City had been preparing for the maintenance of PSC box girder bridges, but the draft maintenance guideline considered overall condition of the bridge and little attention was paid to the condition of tendons. The bridge was evaluated as per the draft guideline and rated as ‘Medium Risk’ although one external tendon was failed. The indices for the evaluation should be properly weighted to prevent failure of tendons.

2012 ◽  
Vol 204-208 ◽  
pp. 2209-2213 ◽  
Author(s):  
Ya Jiang Du ◽  
Bing Wen Yang ◽  
Shui Wan

In the construction of prestressed concrete(PC) box-girder bridge with corrugated steel webs used cast-in-place cantilever method, the key component-corrugated steel webs are fabricated in factory first and then transported to the construction site. Because of the low out-of plane stiffness, corrugated steel webs are easy to deform in the construction, which brings many difficulties for construction. The precision of installing the corrugated steel web has a direct effect on the cross-section shape of the box-girder. So it is a key step to monitor the orientation and installation of corrugated steel web during construction. Based on the experience of some PC box-girder bridges with corrugated steel webs having been built, a method to control the installation accuracy of corrugated steel webs is proposed and some quality assurance measures are introduced in order to ensure the accuracy, reliability and security of the installation of corrugated steel web. The method can be taken as a reference in the construction of this kind of bridge.


Author(s):  
V. Verma ◽  
K. Nallasivam

Purpose: Curved box-girder bridges offers an excellent solution to the problems associated with traffic congestion. However, owing to their complex geometry, they are subjected to shear lag, torsional warping and cross-sectional distortion, which must be assessed in their study and design. Furthermore, the dynamic behaviour of curved bridges adds to the complexity of the issue, emphasizing the importance of studying free vibration. The purpose of this study is to numerically model the concrete curved box-girder bridge considering torsional warping, distortion and distortional warping effects and to identify key parameters that influence the free vibration response of the box-girder bridge by validating it with experimental and analytical studies. Design/methodology/approach: The concrete bridge is numerically modelled by means of computationally effective thin-walled box-beam finite elements that consider torsional warping, distortion and distortional warping, which are prominent features of thinwalled box-girders. The free vibration analysis of the concrete curved box-girder bridge is performed by developing a finite element based MATLAB program. Findings: The identification of critical parameters that influence the free vibration behaviour of curved thin-walled concrete box-girder bridges is one of the main findings of the study. Each parameter and its effect has been extensively discussed. Research limitations/implications: The study limits for the preliminary design phase of thin-walled box-girder bridge decks, where a complete three-dimensional finite element analysis is unnecessary. The current approach can be extended to future research using a different method, such as finite element grilling technique on multi-span curved bridges having unequal span.


Author(s):  
Shubham Sirse ◽  
Kuldeep R. Dabhekar ◽  
Isha P. Khedikar ◽  
M. B. Saiwala

Bridge is the structure which is used for carrying the traffic over the valley or river by connecting highways or railways. There are types of bridges which are T-beam bridges and box girder bridges where the T-beams are effective in resisting bending providing ductility to the bridges. While box girders gives high torsional stiffness providing ductility, stability and also aesthetics. Different codes with varying design philosophy are used for designing these bridges such as IRC:21-2000 and IRC:112-2011. Hence the purpose of this paper is to compare the results of analysis and design of different papers performed using these codes for both the types of bridges i.e. T-beam and box girder bridge. Various researchers studies are available on the design and analysis of T-beam bridge and box girder bridge using IRC:112-2011 and IRC:21-2000. The purpose of this study is to determine the most economical and preferable design code for both T-beam bridges and box girder bridges.


2010 ◽  
Vol 150-151 ◽  
pp. 1022-1025
Author(s):  
Yu Hong Zhang ◽  
Jian Shun Zhang

The impact on curved box girder bridges due to applying prestressing force have been analyzed using finite element method. This paper presents the results of an experimental investigation and analytical studies. Based on the model experiment, the results and conclusions of shear lag in curved box girder with prestressing force are presented that prestressing force has changed shear lag distribution. The prestressing force action on box girder shall be considered comprehensively, structural force shall be analyzed accurately, optimize prestressing tendons shall be set rationally which would make force more rationally. The results highlighted that the impact factors of a curved box girder bridge have been observed to be generally very high, while those of the other responses are also relatively higher than that of corresponding straight box girder bridge.


2012 ◽  
Vol 256-259 ◽  
pp. 1605-1608
Author(s):  
Jin Song Zhu ◽  
Jian Feng Li

Prestressed box-girder bridges have been applied in modern bridges widely as the perfect structural performance, the design method and calculation theory of prestressed box-girder bridges have been relatively perfect. The self-weight of box-girder bridges is reduced during the process of development from concrete structure to composite structure. The prestressed efficiency and the economy are also improved, simultaneously. But up to now, the quantitative research of the effect on efficiency of external prestressing to box-girder bridge with different styles of webs is lack. This paper illustrates the effect on efficiency of external prestressing and economy to box-girder bridge with different styles of webs. The results show that the box-girder bridge with corrugated steel webs has the highest prestressed efficiency and the lowest life cycle cost and the best economy.


2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Chundi Si ◽  
Xin Su ◽  
Enli Chen ◽  
Zhanyou Yan

The objective of this study is to analyse the difference of dynamic response of the deck pavement between a box girder bridge with corrugated steel webs and a concrete web box girder bridge. In this study, a simply supported beam with a span of 34 m is taken as the research object. According to the principle of equal shear stress of the box girder section, the three-dimensional finite element model of the superstructure of two kinds of box girder bridges is established by the finite element software ABAQUS. The DLOAD and UTRACLOAD subroutines are called to impose a movement load on the bridge deck. The dynamic response of the bridge deck pavement under different vehicle speeds (36 km/h, 72 km/h, and 108 km/h) and different load types (single wheel rectangular uniform load and double wheel rectangular uniform load) is calculated. The variation trends of vertical displacement, longitudinal shear stress, and transverse stress of two bridges are compared. The results show that, under the same conditions, the dynamic response of the box girder bridge with corrugated steel webs is greater than that of the equivalent concrete web box girder bridge. The box girder bridge with corrugated steel webs has lightweight, good seismic performance and bending resistance, and more obvious advantages in deflection control. The equivalent concrete web box girder bridge has good shear and torsional properties. The response of two kinds of deck pavement systems of the box girder bridge under dynamic loads is more obvious than that under static loads. This study would provide some theoretical reference for the dynamic response of the deck paving system of box girder bridges.


2013 ◽  
Vol 454 ◽  
pp. 183-186
Author(s):  
Qi Yong You

The calculations of plan truss and beam-girder method on straight bridge were analyzed, which determined right beam-girder method calculation model of the box-girder bridge. Based on this model, the different radius continuous curved box-girder bridges were simulated by finite element, and then the internal forces of the bridge were obtained. The calculations of inner beam and outer beam show the change rule of internal force and bridge radius. The reasonable calculation methods of continuous curved box girder bridges are obtained, which can offer help to the bridge designers.


2010 ◽  
Vol 163-167 ◽  
pp. 3551-3554
Author(s):  
Wei Peng ◽  
Zhi Xiang Zha

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.


Author(s):  
Edward A. Baron

<p>This work consists in identify and assess the properties related to material, geometry and physic sources, in a pre-stressed concrete bridge through a surrogate model. The use of this mathematical model allows to generate a relationship between bridge properties and its dynamic response, with the purpose to develop a tool to predict the analytical values of the studied properties from measured eigenfrequencies. Therefore, it is introduced the identification of damage scenarios, giving the application for validate the generated metamodel (Artificial Neural Network). A FE model is developed to simulate the studied structure, a Colombian bridge called "El Tablazo", one of the higher in the country of this type (box-girder bridge). Once the damage scenarios are defined, this work allows to indicate the basis for futures plans of structural health monitoring.</p>


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.


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