scholarly journals Investigation of Load Distribution Factors for Two-Span Continuous Composite Multiple Boxgirder Bridges

2021 ◽  
Author(s):  
Manal Ibrahim
Keyword(s):  
Load Distribution ◽  
Three Dimensional ◽  
Bending Moment ◽  
Box Girders ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Truck Loading ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Bridges formed of concrete deck slab over built-up steel-box girders are frequently used in bridge construction for their economic and structural advantages. Box girder bridges impose structural challenges to get the straining actions for the design of girders. The objective of this study is to determine the load distribution characteristics for continuous composite multiple–box girder bridges under CHBDC truck loading. An extensive parametric study was conducted using the three-dimensional finite element to evaluate the moment and shear distribution factors when bridges subjected to CHBDC truck loading. The parameters considered in this study are the span length, number of lanes and number of boxes. Then, simple empirical formula for the bending moment and shear force were developed for the structural design. Correlation of the developed expressions based on FEA results with available CHBDC and AASHTO-LRFD formula showed that the former allow engineers to design such bridges more economically and reliably.

scholarly journals Investigation of Load Distribution Factors for Two-Span Continuous Composite Multiple Boxgirder Bridges

2021 ◽  
Author(s):  
Manal Ibrahim
Keyword(s):  
Load Distribution ◽  
Three Dimensional ◽  
Bending Moment ◽  
Box Girders ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Girder Bridges ◽  
Truck Loading ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Bridges formed of concrete deck slab over built-up steel-box girders are frequently used in bridge construction for their economic and structural advantages. Box girder bridges impose structural challenges to get the straining actions for the design of girders. The objective of this study is to determine the load distribution characteristics for continuous composite multiple–box girder bridges under CHBDC truck loading. An extensive parametric study was conducted using the three-dimensional finite element to evaluate the moment and shear distribution factors when bridges subjected to CHBDC truck loading. The parameters considered in this study are the span length, number of lanes and number of boxes. Then, simple empirical formula for the bending moment and shear force were developed for the structural design. Correlation of the developed expressions based on FEA results with available CHBDC and AASHTO-LRFD formula showed that the former allow engineers to design such bridges more economically and reliably.

scholarly journals Investigation of Load Distribution Factors for Simply-Supported Composite Multiple Box Girder Bridges

2021 ◽  
Author(s):  
Siham Kadhim Jawad
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Load Distribution ◽  
Shear Force ◽  
Bending Moment ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Simply Supported ◽  
Girder Bridges ◽  
Load Distribution Factors

Composite box-girder bridges are recently used in modern highway urban system because of their profitable and structural aptitude advantages. North Americans Codes of Practice specify empirical equations for girder moment and shear forces in such bridges in the form of live load distribution factors. These factors were proven to be conservative in some cases and underestimate the response in other cases. Therefore, an extensive parametric study, using the finite-element modeling, was conducted to examine the key parameters that influence the load distribution factors of such bridges. A total of 276 prototype bridges were analyzed to evaluate girder bending moment, shear force and deflection distribution factors for simply-supported composite multiple box-girder bridges when subjected to CHBDC truck loading. Design parameters considered in this study were bridges span length, numbers of design lanes, number of box girders and girder spacing. Based on the data generated from parametric study, sets of simple empirical expressions were developed for bending moment; shear force and deflection distribution factors for such bridges. A correlation between the finite-element results with CHBDC and AASHTO-LRFD empirical expressions showed the former are more reliable in structural design of composite box-girder bridges.

Bracing in completed composite box girder bridges

1984 ◽  
Vol 11 (4) ◽  
pp. 967-977 ◽  
Author(s):  
F. A. Branco ◽  
R. Green
Keyword(s):  
Load Distribution ◽  
Experimental Studies ◽  
Box Girders ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Linear Elastic ◽  
Finite Strip ◽  
Girder Bridges ◽  
Composite Bridges ◽  
Web Stiffeners

During construction, bracing systems are included in box girders to prevent excessive distortion or twist of the sections. The influence of bracing on the deformation of composite bridges during service is examined. A linear elastic finite strip analysis was developed and results are compared with experimental studies from a model and a prototype bridge. The effectiveness of transverse web stiffeners and distortional bracing in preventing distortional stresses is studied. Transverse web stiffeners are effective in resisting distortion of completed girders, and distortional bracing is not essential for stiffened girders. For unstiffened girders, bracing is essential if additional longitudinal stresses due to distortion are not included in design. Interconnecting bracing between boxes is found to be effective in reducing transverse slab moments. Key words: bridges (box girder), bridges (composite), distortion, load distribution, web stiffening, bracing.

scholarly journals Investigation of Load Distribution Factors for Simply-Supported Composite Multiple Box Girder Bridges

2021 ◽  
Author(s):  
Siham Kadhim Jawad
Keyword(s):  
Finite Element ◽  
Parametric Study ◽  
Load Distribution ◽  
Shear Force ◽  
Bending Moment ◽  
Box Girder Bridges ◽  
Box Girder ◽  
Simply Supported ◽  
Girder Bridges ◽  
Load Distribution Factors

Composite box-girder bridges are recently used in modern highway urban system because of their profitable and structural aptitude advantages. North Americans Codes of Practice specify empirical equations for girder moment and shear forces in such bridges in the form of live load distribution factors. These factors were proven to be conservative in some cases and underestimate the response in other cases. Therefore, an extensive parametric study, using the finite-element modeling, was conducted to examine the key parameters that influence the load distribution factors of such bridges. A total of 276 prototype bridges were analyzed to evaluate girder bending moment, shear force and deflection distribution factors for simply-supported composite multiple box-girder bridges when subjected to CHBDC truck loading. Design parameters considered in this study were bridges span length, numbers of design lanes, number of box girders and girder spacing. Based on the data generated from parametric study, sets of simple empirical expressions were developed for bending moment; shear force and deflection distribution factors for such bridges. A correlation between the finite-element results with CHBDC and AASHTO-LRFD empirical expressions showed the former are more reliable in structural design of composite box-girder bridges.

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>

scholarly journals Internal Force on and Deformation of Steel Assembled Supporting Structure of Foundation Pit under Thermal Stress

2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
High Strength ◽  
Element Model ◽  
Internal Force ◽  
Foundation Pit ◽  
Dimensional Finite Element ◽  
Influence Of Temperature On ◽  
Scale Experiment ◽  
Three Dimensional Finite Element

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.

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>

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.

Three-Dimensional Finite Element Analysis of Pipe Flange Connections: The Case of Using Compressed Asbestos Sheet Gasket

2002 ◽  
Author(s):  
Tomohiro Takaki ◽  
Toshimichi Fukuoka
Keyword(s):  
Contact Pressure ◽  
Three Dimensional ◽  
Numerical Procedure ◽  
Bending Moment ◽  
Elastic Interaction ◽  
Bearing Surface ◽  
Element Analysis ◽  
Bolt Stress ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The most important factor for the leakage problem of pipe flange connections is considered to be contact pressure distribution at the gasket bearing surface in service. In this study, the mechanical behaviors of the pipe flange connection are evaluated using FEM as a three-dimensional contact problem, in which a gasket is modeled as a nonlinear one-dimensional gasket element. Here, the contact pressure distributions at the gasket bearing surface and the variations of the bolt stress are estimated under uniform bolt preloads or nonuniform ones due to the elastic interaction during bolting up. The numerical procedure proposed here can successively deal with the processes of bolt-up, applying inner pressure and applying bending moment. The analytical objects are pipe flanges specified in JIS B 2238 with compressed asbestos sheet gaskets being inserted. The validity of the numerical method is ascertained by experiment.

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