Steel Composite Bridges Research Articles

Holistic approach to sustainability of bridges

AbstractBridges are of vital importance for the European infrastructure network. Due to their significance in the political economy, the requirement for sustainable, meaning highly advanced, cost‐effective, environmentally friendly and long‐lived structures is outstanding. Therefore steel composite road bridges were analysed in the Sustainable Steel‐Composite Bridges in Built Environment RFCS project (SBRI) by means of a holistic approach combining Lifecycle Assessment, Lifecycle Costs and Lifecycle Performance analyses to promote steel in the bridge construction. The partners of the project were the Institute of Structural Design Universität Stuttgart, Universidade Coimbra, Institut français des sciences et technologies des transports, de l'aménagement et des réseaux, BRISA Engenharia e Gestão SA and ArcelorMittal.The paper presents a holistic approach to steel and concrete composite bridges by combining analyses of their environmental, economic and functional qualities. The idea of sustainable design is implemented by the project SBRI+ to increase the acceptance of this new way of sustainable thinking, especially among bridge owners and planners. The project includes the SBRI tool which provides designers and authorities with a tool for the evaluation and comparison of the sustainability of different bridge types in the early stages of design, implementing a holistic lifecycle analysis methodology. This helps to select the best option by considering the pros and cons of each alternative in the entire lifespan of the bridge (i.e. construction, operation and end‐of‐life stages) as opposed to the simple comparison of initial construction costs.

Fire resistance of composite steel & concrete highway bridges

In this paper, the effects of geometric skewness and abutment restraint on the fire resistance of a real highway bridge have been studied. Four finite element models have been investigated using rectangular and skew shapes with and without modelling the abutment. The investigation has been carried out in three steps: 1) heat transfer analysis under a specified hydrocarbon fire; 2) simulation of the thermo-mechanical response of the bridge superstructure over the entire duration of the fire using beam and shell elements to represent the structural components; 3) detailed processing and interpretation of the simulation results to understand and illustrate the global response of the structure by comparing all the models. Results indicate that a skew bridge may possess greater inherent resistance to fire. For the two-span highway bridge model, restraint from the abutment does not affect the estimated failure time significantly.

Special heavy plates and steel solutions for bridge building

In many European countries infrastructure, -road as well as railway infrastructure-, needs intensive investments to follow the growing demands of mobility and goods traffic. Steel or steel composite bridges offer in this context viable and very sustainable solutions. Due to its unlimited recyclability steel can in general be seen as the ideal material for such sustainable constructions, but especially when designers or fabricators exploit the nowadays available possibilities of steel industry very cost-efficient and remarkable constructions are realizable. This paper will highlight some of these newest developments in heavy plates for bridge building. For example, for small span railway bridges the so-called thick plate trough bridges have proven to be a favourable concept. Very heavy plates with single plate weights up to 42 t allow building these bridges very efficiently out of one or very few single plates. Another interesting development is the so-called longitudinally profiled plates which allow a varying plate thickness along the actual loading profile. As last point the rising entry of higher strength steels in bridge building will be discussed and it will be shown why thermomechanically rolled plates are the ideal solution for these demands.

Load Capacities of Steel and Concrete Composite Bridge Deck Slab with Haunch

An innovative steel and concrete composite bridge deck slab using bent bars and epoxy as shear connectors was proposed. Four slab specimens with different types of concrete were fabricated and tested to study the load capacities of positive and negative moment regions of the slabs. The cracking and ultimate loads of the specimens were recorded and compared with the results calculated through the reinforced concrete theory and with the design load of the bridge deck slab. It was found that reinforced concrete theory can generally be applied for the proposed slab as well. The effectiveness of the shear connector design of the proposed slab was validated. Meanwhile, the unfavourable effect of the haunch on the shear capacities of the positive moment region of steel and concrete composite bridge deck slab was observed.

Large-span soil steel composite bridges

Large-span soil steel composite bridges

Determination of Load-Carrying Capacity of Railway Steel and Concrete Composite Bridges

In the frame of global European standardization and in consequence of new knowledge related to existing bridges, the need for revision of the service handbook "Determination of load-carrying capacity of railway bridges" grown up. The paper presents general concepts and basic assumptions for determining the railway bridge load-carrying capacity. In contrast to design of a new bridge, additional data related to existing bridge condition and behavior like information from regular inspections and real state of degradation can be taken into account. Based on these data together with the remaining lifetime, a modification of reliability levels for existing bridges based on the mathematic theory of probability can be adopted in the evaluation process. Special attention is also paid to the specific features of determination of load caring capacity of steel-concrete composite bridges in exploitation. Recommendation and allowances for global analysis of existing composite steel and concrete superstructures for the purpose of the load-carrying capacity estimation are discussed as well.

Flexible culverts in sloping terrain: Numerical simulation of avalanche load effects

Avalanche protection concrete structures are expensive and their construction period is often influenced by the climatological conditions at site, which could result in prolonging the erection process and increase its associated costs. Given the short construction time of flexible culverts, such structures can be a cost-effective alternative to traditional protective measures. This article investigates the performance of flexible culverts – often referred to as soil–steel composite bridges (SSCB) – when constructed in sloping topography under avalanche loads. A number of 2D finite element models were created to simulate two case studies composed of a pipe arch and a high-profile arch. The models were generated to investigate the effect of soil cover depth, the avalanche proximity, and the change in soil support conditions around the conduit. The aim was to perceive and understand the changes in deformations and sectional forces under defined avalanche loads. The results enable to realise the effect of shallow soil covers in the pronounced change in bending moments due to avalanches. The proximity of avalanche deviation point has a great influence on the structural performance, though increasing the soil cover depth could considerably help in reducing the bending moments resulting from avalanches. It is also found that the downhill soil support configuration has a substantial effect on the flexural response of the structure.

Design and construction of a launched steel girder bridge

This paper describes the design and construction of the steel composite Bridge G4 as part of the recently completed Egnatia Motorway project in northern Greece. The bridge crosses a 180 m wide, 70 m deep valley situated in a seismic zone. Following a value engineering study, a three-span bridge with incrementally launched deck was found to provide the best option with minimal disturbance to the environment. Due to the relatively high seismic design acceleration, the superstructure is considered to float on the substructure by means of high damping lead rubber bearings restrained by mechanical dampers at abutments. This paper describes the design and construction of Bridge G4.

Flexible culverts in sloping terrain: Numerical simulation of soil loading effects

This paper investigates the performance of flexible culverts – often referred to as soil–steel composite bridges (SSCB) – when constructed in sloping topography. A number of 2D finite element models were created to simulate three case studies compromising two pipe arches and one high profile arch. The models were generated to investigate the effect of different surface slopes for different depths of soil cover. The aim was to understand and perceive the change of sectional forces in the structure with respect to slope increase under different soil covers. In addition, the effect of structure presence in the soil was also investigated in terms of soil stability. The results enable to realize the susceptibility of such structures to low heights of soil cover when built in sloping environment, which is seen in the incremental change in displacements and sectional forces, specially the bending moments. It is also found that the geometrical aspects of the profile shapes have more pronounced effect on their performance when introducing steeper slopes. The safety factor of soil stability is found to decrease when introducing such structures in the soil.

Design of Soil–Steel Composite Bridges

The research work presented in this paper deals with what are commonly known as soil-steel flexible culverts. The word culvert is, however, usually associated with small pipes in road embankments. Over the years, the flexible culverts have grown bigger and today they are what one could call bridges; they are not just culverts anymore. A more proper name today would therefore be Soil-Steel Composite Bridges. This explains the title of the paper. The research work has been ongoing for more than 30 years at the Department of Civil and Architectural Engineering, Division of Structural Engineering and Bridges, at KTH Royal Institute of Technology in Stockholm, Sweden. Realizing that spans have grown larger and heights of cover smaller, the aim was to develop a design method that could be used in everyday design work. The design method developed, based on theoretical studies as well as several full scale tests, is today a code requirement in Sweden, Finland, and Norway and is also in use in several other countries in Europe. This paper describes the design method itself and the development behind it as well as ongoing research and planned future developments.

Influence of Maintenance Strategies on the Life Cycle Performance of Composite Highway Bridges

In the context of sustainability, life cycle approaches are becoming increasingly popular for the assessment of potential impacts of a product or a system, from raw materials production to decommissioning and end-of-life processes. In relation to highway bridges, lifetime analysis implies consideration of the way the bridge is maintained over the lifespan of the analysis. Different maintenance strategies can be defined depending on the policy followed by highway administrations, which are usually subject to budget restraints. An overview of different European practices in the maintenance of highway bridges is provided in this paper; then, a methodology for life cycle analysis of bridges is presented, which enables assessment of the influence of different strategies of maintenance of highway bridges, in terms of environmental burdens, and direct and indirect costs over the lifespan of the bridge. The discussion is based on a case study of a composite bridge crossing a dual carriageway. The methodology presented in this paper is part of a research work carried out in the framework of the European research project SBRI: Sustainable Steel-Composite Bridges in Built Environment.

Vertical ground motion influence on seismically isolated & unisolated bridges

In this study, influences of vertical ground motion on seismically isolated bridges were investigated for seven different earthquake data. One assessment of bearing effect involves the calculation of vertical earthquake load on the seismically isolated bridges. This paper investigates the influence of vertical earthquake excitation on the response of briefly steel girder composite bridges (SCB) with and without seismic isolation through specifically selected earthquakes. In detail, the bridge is composed of 30m long three spans, concrete double piers at each axis supported by mat foundations with pile systems. At both end of the spans there exists concrete abutments to support superstructure of the bridge. SCBs which were seismically isolated with ten commonly preferred different lead-rubber bearings (LRB) under each steel girder were analyzed. Then, the comparisons were made with a SCB without seismic isolation. Initially, a preliminary design was made and reasonable sections for the bridge have been obtained. As a result of this, the steel girder bridge sections were checked with AASHTO provisions and analytical model was updated accordingly. Earthquake records were thought as the main loading sources. Hence both cases were exposed to tri-axial earthquake loads in order to understand the effects under such circumstances. Seven near fault earthquake data were selected by considering possession of directivity. Several runs using the chosen earthquakes were performed in order to be able to derive satisfactory comparisons between different types of isolators. Analytical calculations were conducted using well known structural analysis software (SAS) SAP2000. Nonlinear time history analysis was performed using the analytical model of the bridge with and without seismic isolation. Response data collected from SAS was used to determine the vertical load on the piers and middle span midspan moment on the steel girders due to the vertical and horizontal component of excitation. Comparisons dealing with the effects of horizontal only and horizontal plus vertical earthquake loads were introduced.

Economic Analysis of Bridges Project Rehabilitation

The goal of this paper is to point out the advantage of economic analysis to assess a rehabilitation of bridges.The paper includes specific calculations and the results of the economic efficiency of the project, by using well know economic methods in the evaluation of two interchangeable technological variants of the bridge project rehabilitation. The methods are quantified and compare the economic performance alternative to monolithic prestressvariant of composite steel and concrete bridge. The paper reflects the current practice of economic and financial analysis recommended by the Ministry of Transport, Construction and Regional Development.

Steel Bridges. Conceptual and Structural Design of Steel and Steel‐Concrete Composite Bridges. Von J.‐P. Lebet, M. A. Hirt

StahlbauVolume 83, Issue 9 p. 682-682 Rezensionen Steel Bridges. Conceptual and Structural Design of Steel and Steel-Concrete Composite Bridges. Von J.-P. Lebet, M. A. Hirt Prof. Dr.-Ing. Karsten Geißler, Prof. Dr.-Ing. Karsten Geißler BerlinSearch for more papers by this author Prof. Dr.-Ing. Karsten Geißler, Prof. Dr.-Ing. Karsten Geißler BerlinSearch for more papers by this author First published: 01 September 2014 https://doi.org/10.1002/stab.201490142Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article.Citing Literature Volume83, Issue9September 2014Pages 682-682 RelatedInformation

Dynamic behaviour of a short span soil–steel composite bridge for high-speed railways – Field measurements and FE-analysis

The dynamic response from passing trains at high speed is studied for a short span soil–steel composite bridge. Field measurements have been performed, comprising steel strains, vertical crown displacements and accelerations in the steel and the backfill. Soil material damping properties are estimated through analysis of the field measurements. Approaches for numerical modelling are presented, focusing on the dynamic response from passing trains. Both 2D and 3D continuum models are compared with the measured response. Based on the models, the influence of the Young’s modulus of the backfill on the bridge behaviour is investigated. The 3D-model also enables estimation of the load distribution, which is found to increase at higher train speeds. An effective width to be used in 2D analyses is proposed. A dynamic design check using the high-speed train load models in the Eurocode is presented, that for the studied bridge envisage a resonance peak at about 320km/h.

Análisis comparativo del diseño de un puente mixto mediante Eurocódigo y AASHTO LRFD

The basic design parameters and results obtained in a composite steel and concrete bridge using Structural Eurocodes and the American Code AASHTO LRFD Bridge Design Specifications are compared in this paper. Internal efforts, stresses and the main structural verifications in composite girders are analyzed for a two span continuous composite bridge. The bridge deck is composed by four I steel girders and an upper concrete slab linked to the girders by shear stud connectors all along its length. This bridge can be considered as representative of a highway overpass or even a highway bridge. The most relevant conclusions regarding the way the analysis and verifications are treated in each code are briefly exposed in this paper as well as the main differences in the bridge design from quantities point of view.© 2013, Asociación Científico-Técnica del Hormigón Estructural (ACHE). Published by Elsevier España, S.L. All rights reserved.

Experimental and numerical study on mechanical behavior of an adhesively-bonded joint of FRP–steel composite bridge under shear loading

Due to the composite action between the Fiber-Reinforced Polymer (FRP) decks and steel girders, the deck and girder tend to bend together to carry the loading, which induce the shear stress in the adhesively-bonded joint between them. This paper presents an experimental and numerical study of the adhesively-bonded joint under shear loading. The experimental study shows that the average ultimate failure load of specimens pretreated by using sand paper and sand blasting is more than three times of that of specimens pretreated by only using acetone. Further comparison on failure modes confirms that the sufficient surface pretreatment can improve the bonding quality between the adhesive layer and the steel support. Subsequently, a three dimensional Finite Element (FE) numerical model is developed using ABAQUS 6.8. The FE analysis results are validated by experimental works, focusing on the shear deformational response of the adhesively-bonded joints. With the validated FE model, three-dimensional nature of the stress distribution and stress singularity at the interface between the adhesive layer and the steel support are investigated. Further study is performed on the mesh density of the FE model, to investigate the mesh dependence of stress distribution.

Determination of Stiffness of the Connections of Composite Steel and Concrete Bridge Deck by the Limit Permissible Deflections

The composite steel and concrete structures are used for constructing bridge floors and others buildings. The joint action of composite structures as well as their economic efficiency depends on the connection between the layers, i.e. stiffness of the steel beam and the concrete slab. Under the effect of external load in the connection of steel and concrete the shear deformations occur. The size of these deformations depends on the effective shear stiffness of the connection of layers. When designing the composite steel and concrete structures it is very important to accurately calculate their deflections. Deflection is largely dependent on the stiffness of the connection of steel and concrete. In isolated cases it is purposive to calculate the necessary stiffness of the connection of steel and concrete taking into consideration the permissible deflection of the composite steel and concrete structure. This paper gives the methodology which, based on the known permissible deflection of the structure, allows to calculate the necessary equivalent effective shear modulus of the steel-concrete connection. Experimental investigations of the composite steel and concrete beams were carried out. Deflections of the composite beams, also the shear deformations of steel and concrete connections and the effective shear stiffness of this connection were determined. Theoretical calculations of the effective shear stiffness of the connection of concrete slab and steel beam of the experimental composite steel and concrete beams were conducted. Investigations showed a rather good correspondence between the experimental and theoretical investigation results.

Calibration of Turkish LRFD bridge design code for slab on steel plate girders

In Turkish design practice, slab on steel composite I-girder bridges have been designed to span between 50 and 80 meters. To date, modified versions of the AASHTO LFD (Load Factor Design) or ASD (Allowable Stress Design) requirements are adapted in Turkey. The recent switch of the U.S. bridge codes to Load Resistance Factor Design (LRFD) method also necessitates the calibration of the Turkish LRFD design code that is under development. In this on-going research, it has been determined that the current Turkish design truck is not very appropriate to be used in design of bridges with span lengths in excess of 50 meters. The main aim of this study is to define a new type of live (truck) load to be used in the basic gravity load combination, as well as to develop the corresponding load factors to be implemented in the design of slab on steel composite I-girder bridges. In this scope, usually a target reliability index is selected to reflect the safety level of current design practice based on the uncertainties associated with the design parameters. For the basic gravity load combination, which includes the dead and live loads, a minimum target reliability of 4.00 is selected, instead of 3.50 that have been used in the U.S. In the statistical computations of the reliability index, the quantification of uncertainties is made based on local data supplemented by information compiled from relevant international literature.

Mechanical Properties of Shear Stud during and after Fire

Many examples of a bridge damaged due to accidental or incendiary fire heating up the bridge from below have been reported. When steel and concrete composite girder bridges are exposed to fire, it is important to understand the progression of damage to the shear connections. However, determination of the level of damage to the shear connection in experimental tests is a challenge. Furthermore, the postfire performance of the shear connection is not clear yet. To better understand the mechanical properties of the shear stud during and after fire, the authors conducted three different push-out tests of heated studs, in which the fire temperature varied from 300 to 700°C over a period of 90 min. From the results of the static push-out tests conducted after heating, it was found that the maximum shear resistance of shear studs is marginally affected by the heating, but the slip constant was decreased remarkably in proportion to the heating temperature. Furthermore, the fatigue strength of shear studs showed remarkable decrease due to the undesirable slip behavior.