scholarly journals Computation of Deflections for PC Box Girder Bridges with Corrugated Steel Webs considering the Effects of Shear Lag and Shear Deformation

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Wei Ji ◽  
Kui Luo ◽  
Jingwei Zhang
Keyword(s):  
Shear Deformation ◽  
Prestressed Concrete ◽  
Displacement Function ◽  
Shear Lag ◽  
Longitudinal Displacement ◽  
Box Girders ◽  
Element Analysis ◽  
Box Girder ◽  
Bridge Model ◽  
Bridge Models

Prestressed concrete (PC) girders with corrugated steel webs (CSWs) have received considerable attention in the past two decades due to their light self-weight and high prestressing efficiency. Most previous studies were focused on the static behavior of CSWs and simple beams with CSWs. The calculation of deflection is an important part in the static analysis of structures. However, very few studies have been conducted to investigate the deflection of full PC girders or bridges with CSWs and no simple formulas are available for estimating their deflection under static loads. In addition, experimental work on full-scale bridges or scale bridge models with CSWs is very limited. In this paper, a formula for calculating the deflection of PC box girders with CSWs is derived. The longitudinal displacement function of PC box girders with CSWs, which can consider the shear lag effect and shear deformation of CSWs, is first derived. Based on the longitudinal displacement function, the formula for predicting the deflection of PC box girders with CSWs is derived using the variational principle method. The accuracy of the derived formula is verified against experimental results from a scaled bridge model and the finite element analysis results. Parametric studies are also performed, and the influences of shear lag and shear deformation on the deflection of the box girder with CSWs are investigated by considering different width-to-span ratios and different girder heights. The present study provides an effective and efficient tool for determining the deflection of PC box girders with CSWs.

Study of Shear Deformation's Influence on Deflection of Continuous Composite Box-Girder Bridge with Corrugated Steel Webs

2013 ◽  
Vol 275-277 ◽  
pp. 961-965
Author(s):  
Ming Min Tang ◽  
Li Chao Su ◽  
Shui Wan
Keyword(s):  
Shear Deformation ◽  
Water Diversion ◽  
Uniform Load ◽  
Box Girders ◽  
Concentrated Force ◽  
Element Analysis ◽  
Box Girder ◽  
North Water ◽  
Box Girder Bridge ◽  
Girder Bridge

Taking South-to-North Water Diversion Bridge, a continuous composite box-girder bridge with corrugated steel webs, as the engineering background, the cantilever beam end’s deflection calculation formulae considering shear deformation were deduced by using energy method. Comparing with finite-element analysis (FEA) values and measured values, the formulae which considered both concentrated force and uniform load have enough accuracy. Results show that, shear deformation’s proportion is more obvious in overall deflection of such box-girders which have smaller span ratio, and it’s more than 30%. For continuous composite box-girder bridge with corrugated steel webs, contribution of shear deformation to overall deflection should not be ignored.

Mechanical Properties Analysis of CFRP Pre-Stressed Section Continuous Thin-Walled Box Girder Bridge Models 22

2014 ◽  
Vol 624 ◽  
pp. 592-595
Author(s):  
Xin Zhong Wang ◽  
Chuan Xi Li
Keyword(s):  
Prestressed Concrete ◽  
Material Model ◽  
Prestress Loss ◽  
Box Girder ◽  
Concrete Material ◽  
Bridge Model ◽  
Change Trend ◽  
Box Girder Bridge ◽  
Girder Bridge ◽  
Bridge Models

An externally pre-stressed continuous box girder bridge model is designed according to loading features of the continuous beam. The CFRP bars and steel strands are used to make two models for externally pre-stressed reinforcements Analysis of the two models under three different load stiffness and loss of prestress, through calculation and analysis, found that two kinds of prestressed concrete material model under three load deflection basic same, also almost the same change trend, prestressed RMS model than model 1, 2 but with the increase of load model 2 prestress loss is big. Analysis results of CFRP materials and application to provide the reference in the bridge.

scholarly journals Effect of Construction Method on Shear Lag in Prestressed Concrete Box Girders

2012 ◽  
Vol 2012 ◽  
pp. 1-17 ◽  
Author(s):  
Shi-Jun Zhou
Keyword(s):  
Cross Sections ◽  
Prestressed Concrete ◽  
Construction Process ◽  
Shear Lag ◽  
Box Girders ◽  
Box Girder ◽  
Construction Methods ◽  
Concrete Box Girder ◽  
Concrete Box Girder Bridges ◽  
Girder Bridge

Most of the previous researches conducted on shear lag of box girders were only concerned about simple types of structures, such as simply supported and cantilever beams. The structural systems concerned in these previous researches were considered as determined and unchangeable. In this paper, a finite element method considering shear lag and creep of concrete was presented to analyze the effect of dynamic construction process on shear lag in different types of concrete box-girder bridges. The shear lag effect of the three types of a two-span continuous concrete beam classified by construction methods was analyzed in detail according to construction process. Also, a three-span prestressed concrete box-girder bridge was analyzed according to the actual construction process. The shear lag coefficients and stresses on cross sections along the beam including shear lag were obtained. The different construction methods, the changes of structural system with the construction process, the changes of loading and boundary conditions with the construction process and time, the prestressing, and creep were all imitated in the calculations. From comparisons between the results for beams using different construction methods, useful conclusions were made.

scholarly journals Prediction of Shear Lag Effect in Thin-Walled Single-Box Multicell Box Girder Based on the Modified Warping Displacement Function

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Xiayuan Li ◽  
Shui Wan ◽  
Kongjian Shen ◽  
Peng Zhou ◽  
Xiao Wang
Keyword(s):  
Internal Force ◽  
Displacement Function ◽  
Force Balance ◽  
Shear Lag ◽  
Shear Lag Effect ◽  
Box Girders ◽  
Box Girder ◽  
Lag Effect ◽  
Warping Displacement ◽  
Thin Walled

In this study, an effective and accurate theoretical analysis method for predicting the shear lag effect in the thin-walled single-box multicell box girder is presented. The modifications of longitudinal warping displacement functions at the flanges are fully investigated, including the shear lag width (bij) of flanges, the coefficients (αij) of shear lag warping functions, the deformation compatibility conditions in flanges, and the internal force balance (D). The initial shear deformation (γ03) in the top lateral cantilever flanges is innovatively introduced in multicell box girders and obtained by the designed procedure. In addition, the transverse distribution function for describing the longitudinal warping displacement is deduced and expressed in the form of the cosine function. Based on the principle of minimum potential energy, the governing differential equations are derived and solved with the associated boundary and load conditions. The accuracy and applicability of the proposed method (SL-THY2) are validated for four thin-walled single-box multicell (two- and three-cell) box girders with the results derived from the solid finite element method.

Evaluation of web reinforcements in prestressed concrete box girders through shear-transverse bending domains

2020 ◽  
pp. 136943322098170
Author(s):  
Michele Fabio Granata ◽  
Antonino Recupero
Keyword(s):  
Analytical Model ◽  
Prestressed Concrete ◽  
3D Analysis ◽  
Box Girders ◽  
Element Analysis ◽  
Cross Sectional ◽  
Interaction Domains ◽  
Global And Local ◽  
Resultant Forces

In concrete box girders, the amount and distribution of reinforcements in the webs have to be estimated considering the local effects due to eccentric external loads and cross-sectional distortion and not only the global effect due to the resultant forces of a longitudinal analysis: shear, torsion and bending. This work presents an analytical model that allows designers to take into account the interaction of all these effects, global and local, for the determination of the reinforcements. The model is based on the theory of stress fields and it has been compared to a 3D finite element analysis, in order to validate the interaction domains. The results show how the proposed analytical model allows an easy and reliable reinforcement evaluation, in agreement with a more refined 3D analysis but with a reduced computational burden.

Beam finite element for thin-walled box girders considering shear lag and shear deformation effects

2021 ◽  
Vol 233 ◽  
pp. 111867
Author(s):  
Xiayuan Li ◽  
Shui Wan ◽  
Yuanhai Zhang ◽  
Maoding Zhou ◽  
Yilung Mo
Keyword(s):  
Finite Element ◽  
Shear Deformation ◽  
Shear Lag ◽  
Box Girders ◽  
Thin Walled

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.

A finite beam element for analyzing shear lag and shear deformation effects in composite-laminated box girders

2004 ◽  
Vol 82 (9-10) ◽  
pp. 763-771 ◽  
Author(s):  
Yaping Wu ◽  
Yuanming Lai ◽  
Xuefu Zhang ◽  
Yuanlin Zhu
Keyword(s):  
Shear Deformation ◽  
Beam Element ◽  
Shear Lag ◽  
Box Girders

scholarly journals Influence of end Contsrains on the Global Behaviour of a Box Girder

2016 ◽  
Vol 6 (1) ◽  
pp. 7-15
Author(s):  
Daniela Mihaela Boca ◽  
A. Faur ◽  
A. Boca
Keyword(s):  
Prestressed Concrete ◽  
Transport Infrastructure ◽  
Box Girders ◽  
3D Fem ◽  
Important Data ◽  
Box Girder ◽  
Fem Model ◽  
Global Behaviour ◽  
Applied Forces ◽  
Precast Prestressed Concrete

Abstract This study aims to presents the importance of end constrains, boundary conditions and position of the applied forces regarding the design of precast/prestressed concrete box girders. The study is based on a destructive test which was performed on a 37.1 m span single-cell prestressed concrete box girder. The scope of the test was to certify the usage of such girders for the new Transylvania motorway bridges. The test is numerically reproduced through a full 3D FEM model implemented in SAP2000. The influence of the end diaphragms is considered by analysing the beam’s behaviour to six loading conditions: one of which is replicating the loadings during the test, while the others are conceived as real vertical and horizontally loading scenarios. The results obtained for the girders with and without end constrains are compared. The performances of both design solutions in the presence of prestressing are highlighted where applicable. It is considered that the results of this study may provide very important data if considering that Romania has an urgent need to realize a modern and an adequate transport infrastructure.

scholarly journals Analysis of Pure Bending Vertical Deflection of Improved Composite Box Girders with Corrugated Steel Webs

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Chi Ma ◽  
Shi-zhong Liu ◽  
Jin Di ◽  
Rui-jie Zhang
Keyword(s):  
Shear Deformation ◽  
Analytical Solutions ◽  
Analytical Calculation ◽  
Load Condition ◽  
Width Ratio ◽  
Shear Lag ◽  
Vertical Deflection ◽  
Box Girders ◽  
Concentrated Load ◽  
Span Width

Steel bottom plates are applied as replacements for the concrete bottom plates in order to reduce the dead weight of the composite box girders with corrugated steel webs and steel bottom plates (CSWSB). Due to the change in the material, the previous analytical calculation methods of vertical deflection of composite box girders with corrugated steel webs (CSWs) cannot be directly applied to the improved composite box girders. The shear lag warpage displacement function was derived based on the shear deformation laws of the upper flange and the bottom plates of the improved composite box girders. The equations for the calculation of the shear deformation and the additional deflection due to the shear lag of continuous and simply supported composite box girders with CSWSB under concentrated and uniformly distribution loads were derived by considering the double effects of the shear lag and the shear deformations of the top and the bottom plates with different elastic moduli. The analytical solutions of the vertical deflection of the improved composite box girders include the theory of the bending deflection of elementary beams, shear deformation of CSWs, and the additional deflection caused by the shear lag. Based on the theoretical derivation, an analytical solution method was established and the obtained vertical deflection analytical solutions were compared with the finite element method (FEM) calculation results and the experimental values. The analytical equations of vertical deflection under the two supporting conditions and the two load cases have verified the analyses and the comparisons. Further, the additional deflections due to the shear lag and the shear deformation are found to be less than 2% and 34% of the total deflection values, respectively. Moreover, under uniform distributed load conditions, the deflection value was found to be higher than that of the under concentrated load condition. It was also found that the ratio of the deflection caused by the shear lag or the shear deformation to the total deflection decreased gradually with the increase in the span width ratio. When the value of the span width ratio of a single box and single chamber composite box girder with CSWSB was equal to or greater than 8, the deflections caused by the shear lag and the shear deformation could be ignored.

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