Influence of Various Inclinations of Webs on Anti-Torsion Characteristic of Steel-Concrete Composite Box Girder

2012 ◽  
Vol 166-169 ◽  
pp. 60-63
Author(s):  
Xu Hui Hu
Keyword(s):  
Fem Analysis ◽  
Base Plate ◽  
Analysis Software ◽  
Box Girders ◽  
Box Girder ◽  
The Web ◽  
Research Show ◽  
Concrete Stress

Applying FEM Analysis Software to the analysis that under the conditions of webs with inclinations of 15°，20°，25°，30°，35°，40°, the girders appear mid-span transformation, the concrete stress of the base plate and the stress of the steel webs at the fulcrum. The results of the research show that the increase of the inclination of the web can facilitate the anti-torsion performance of the composite box girders.

Prefabrication and Erection Technology of Wide Box Girders in Cross-Sea Bridge

2014 ◽  
Vol 1065-1069 ◽  
pp. 882-888
Author(s):  
Yue Huang ◽  
Xing Fa Wu
Keyword(s):  
Great Influence ◽  
Dead Load ◽  
Box Girders ◽  
Box Girder ◽  
Technical Problems ◽  
Line Segments ◽  
Temperature Load ◽  
Quanzhou Bay ◽  
Research Show ◽  
Better Than

In the approach spans of Quanzhou Bay Cross-sea Bridge, these standard spans are 50m or 70m , width is 20.05m.The approach spans have been built by using short Line segments precast and erection method. This is the first application in the cross sea bridges. According to characteristics of this project, the research on prefabrication and erection technology of wide box girders has been carried out to solve the technical problems in the process of construction. The research show that: 1)In precasting process , the vertical deformation of wide box girder is very small under dead load and temperature load etc. so the influence of prefabrication and erection accuracy can be ignored; 2)The temporary anchor using prestressed steel strand better than planished steel; 3) When using epoxy gasket to adjust geometric line shape, the thickness of cemented layer has a great influence on the linear adjustment;4)The epoxy gasket and bridge erecting machine should be used together, Alignment adjustmen could obtain satisfactory results.

Analytical Study on Curved Box Girder Bridges with Minimum Horizontal Stiffeners

2019 ◽  
Author(s):  
Junichi Adachi ◽  
Takashi Yamaguchi ◽  
Kohei Funayama ◽  
Shintaro Arai ◽  
Michiaki Takao
Keyword(s):  
Ultimate Strength ◽  
Urban Areas ◽  
Structural Parameters ◽  
Bending Moment ◽  
Automatic Welding ◽  
Box Girders ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
The Web

<p>Curved box girder bridges are widely used in viaducts in urban areas, as well as highway junctions. In fabricating curved box girders, automatic welding robots cannot be applied to welding of horizontal stiffeners to the web panel due to the girder curvature and manufacturing costs increase. <span>Elimination or reduction of the number of horizontal stiffeners is desirable. In this study, </span>FE analysis was carried out varying the curvature and the width-thickness ratio of the structural components as structural parameters to propose the curved box girder bridges without horizontal stiffeners in the web panel. In order to evaluate <span>the ultimate strength, the collapse mode (buckling of lower flange, web panel or stiffeners) has been clarified considering the </span>design sectional forces such as torsional moment, bending moment and shearing force.</p><p>From the results, it was found that the curvature has little influence on the bending buckling strength of the web panels. Even if the horizontal stiffeners are eliminated, the ultimate strength doesn’t decrease until compressive flange buckling occurs. It is concluded that the ultimate strength is governed by the buckling of the compressive flange, even when the bending buckling occurs in the web panel.</p>

Structural topology optimization of bridge girders in cable supported bridges

2018 ◽  
Author(s):  
Mads Baandrup ◽  
Ole Sigmund ◽  
Niels Aage
Keyword(s):  
Topology Optimization ◽  
Large Scale ◽  
Design Method ◽  
Optimization Method ◽  
Bridge Girders ◽  
Structural Topology ◽  
Box Girders ◽  
Box Girder ◽  
Fine Mesh ◽  
Further Development

<p>This work applies a ultra large scale topology optimization method to study the optimal structure of bridge girders in cable supported bridges.</p><p>The current classic orthotropic box girder designs are limited in further development and optimiza­ tion, and suffer from substantial fatigue issues. A great disadvantage of the orthotropic girder is the loads being carried one direction at a time, thus creating stress hot spots and fatigue problems. Hence, a new design concept has the potential to solve many of the limitations in the current state­ of-the-art.</p><p>We present a design method based on ultra large scale topology optimization. The highly detailed structures and fine mesh-discretization permitted by ultra large scale topology optimization reveal new design features and previously unseen eff ects. The results demonstrate the potential of gener­ ating completely different design solutions for bridge girders in cable supported bridges, which dif­ fer significantly from the classic orthotropic box girders.</p><p>The overall goal of the presented work is to identify new and innovative, but at the same time con­ structible and economically reasonable, solutions tobe implemented into the design of future cable supported bridges.</p>

Strengthening of box girder bridges with external prestressing - case study for the Langeland Bridge.

2021 ◽  
Author(s):  
Ulrik Sloth Andersen
Keyword(s):  
Additional Analysis ◽  
Box Girders ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Basic Principles ◽  
Structural Assessment ◽  
South Eastern ◽  
Girder Bridges ◽  
External Prestressing

<p>This paper presents the basic principles for strengthening of bridges and other structures through the use of external prestressing. A case study that includes strengthening of the approach spans for the Langeland Bridge in the south-eastern part of Denmark is included.</p><p>During a recent rehabilitation, corrosion of the post-tensioned tendons was discovered inside the box girders of the bridge. Additional analysis of the extent of the corrosion and a structural assessment was undertaken. Based on this, a strengthening project was carried out, and strengthening with external prestressing is currently being implemented.</p>

Tame Valley Viaduct Assessment and Strengthening

2016 ◽  
Author(s):  
Sarah Jane Blick ◽  
Chris West
Keyword(s):  
Reinforced Concrete ◽  
Design Process ◽  
Composite Structure ◽  
Concrete Slab ◽  
City Centre ◽  
Box Girders ◽  
Reinforced Concrete Slab ◽  
Current Loading ◽  
The Web

Tame Valley Viaduct is a 620m long multi-span highway structure linking Birmingham city centre to the M6 motorway. An assessment in 2004 found the capacity of the structure to be inadequate for current loading, resulting in a requirement for strengthening. Before strengthening works were designed, a comprehensive, refined re-assessment of the structure was undertaken to fully define which areas needed strengthening and which did not. The composite structure comprises a reinforced-concrete slab and typically four longitudinal steel box girders. Each of these longitudinal girders comprises approximately 600 sets of web and flange panels. The scale of the task required automation of the assessment and design process. This paper discusses how the automation was undertaken including the preparation of models to calculate individual panel loading, assessment of the web and flange panels, and the checking of strengthening solutions.

Design of segmental box girder bridges with match cast dry joints in Melbourne, Australia

2021 ◽  
Author(s):  
Adam McManus ◽  
Daniel Tofful ◽  
Rafal Wozniak
Keyword(s):  
Recent Work ◽  
Level Crossing ◽  
Box Girders ◽  
Design Standards ◽  
The West ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Linear Infrastructure ◽  
Current Standards

<p>A study of recent work undertaken on the Caulfield to Dandenong Level Crossing Removal Project and West Gate Tunnel Project in Melbourne Australia. The viaducts on these projects were precast segmental box girders erected span-by-span with match cast dry joints which present several key advantages in brownfield construction of linear infrastructure.</p><p>These case studies consider the application of Australian and International design standards to the design of Australian Infrastructure. It is acknowledged that international design standards such as AASHTO have moved away from the use of match cast dry joints however in the Australian context they are still relevant, and it has been necessary to interrogate current standards to establish a suitable design basis. This approach is imperative when assessing existing infrastructure like recent work on the West Gate Tunnel Project which involved the assessment of the existing precast segmental City Link Viaducts. This study seeks to present recommendations on how AS5100.5 may be modified to provide a more practical and efficient solution for the design of new and the assessment of existing infrastructure.</p>

scholarly journals Numerical Analysis of Temperature Influence on Transverse Cracks in Concrete Box-Girder Bridges

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Hanzheng Xu ◽  
Xiaofeng Yan
Keyword(s):  
Numerical Analysis ◽  
Highway Bridges ◽  
Hydration Reaction ◽  
Box Girders ◽  
Transverse Cracks ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Concrete Box Girder ◽  
Concrete Box Girder Bridges

Concrete box-girder bridges are widely used in China. During several routine inspections of two-year-old highway bridges of this type in the China Central Plains region, we found that transverse cracks are widespread on the bottom flanges of those box girders, mainly distributed in the area of 1/4L to 3/4L of the span. Selected cracks were then monitored continuously for one year. Our results showed that there had been no change in the widths of the cracks, but their lengths had increased and new cracks had formed. Taking into consideration factors like hydration reaction, relative humidity difference, shrinkage and creep, sunlight thermal differential effect, sudden temperature change, vehicle load, and their combined efforts, we have developed spatial structural models and conducted stress analyses on the reinforced concrete and prestressed concrete box-girder bridges, respectively. Our numerical analysis results indicated that the hydration reaction is the main reason for the initial bottom flange crack and the temperature difference between the inside and the outside of the box girders caused the crack developments at the later stage.

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 Acoustic Emission Monitoring of Multicell Reinforced Concrete Box Girders Subjected to Torsion

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Marya Bagherifaez ◽  
Arash Behnia ◽  
Abeer Aqeel Majeed ◽  
Chai Hwa Kian
Keyword(s):  
Acoustic Emission ◽  
Reinforced Concrete ◽  
Cross Sections ◽  
Analysis Data ◽  
Damage Localization ◽  
Box Girders ◽  
Box Girder ◽  
Value Analysis ◽  
Damage Propagation ◽  
Torsion Fracture

Reinforced concrete (RC) box girders are a common structural member for road bridges in modern construction. The hollow cross-section of a box girder is ideal in carrying eccentric loads or torques introduced by skew supports. This study employed acoustic emission (AE) monitoring on multicell RC box girder specimens subjected to laboratory-based torsion loading. Three multicell box girder specimens with different cross-sections were tested. The aim is to acquire AE analysis data indicative for characterizing torsion fracture in the box girders. It was demonstrated through appropriate parametric analysis that the AE technique could be utilized to effectively classify fracture developed in the specimens for describing their mechanical behavior under torsion. AE events localization was presented to illustrate the trend of crack and damage propagation in different stages of fracture. It could be observed that spiral-like patterns of crack were captured through AE damage localization system and damage was quantified successfully in different stages of fracture by using smoothedb-value analysis.

Estimation of Ultimate Longitudinal Bending Moment of Ships and Box Girders

1996 ◽  
Vol 40 (03) ◽  
pp. 244-257 ◽  
Author(s):  
M. K. Rahman ◽  
M. Chowdhury
Keyword(s):  
Cross Section ◽  
Bending Moment ◽  
Fortran Program ◽  
Box Girders ◽  
Limit States ◽  
Box Girder ◽  
Stiffened Panels ◽  
Complete Procedure ◽  
Longitudinal Bending ◽  
Collapse Behavior

The paper describes a methodology of computing the ultimate value of the longitudinal bending moment at any cross section of a ship or box girder. The cross section has been discretized into stiffened panels (one stiffener with its associated effective plating). The limit states for these panels, both tensile and compressive, are modeled in an appropriate manner. Since the ultimate strength of the girder section is largely governed by the behavior of the panels under compression, the authors have paid special attention in modeling the collapse as well as post-collapse behavior of these panels. A new stress-strain relationship is also introduced. The complete procedure has been coded into a FORTRAN program and tested against a number of box girder models and an actual ship for which the true behavior was known. The results obtained from the proposed program appear to be quite satisfactory. Good correlation was also found when compared with the results obtained by more complex and rigorous analytical methods.

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