Steel Bridge Construction Research Articles

Sequence effects on the life estimation of welded tubular structures made of S355J2H under uniaxial fatigue loading

The use of hollow sections to form lightweight structures is widespread in common steel processing industries such as crane, commercial vehicle, steel bridge and agricultural machinery construction. The hollow sections are mainly designed as truss or frame structures, in some cases using high-strength and higher-strength steels in order to achieve optimum utilization of the component and material. A new collection of fatigue life data covering sequence effects and the accuracy of the linear damage accumulation is presented. Effects of the shape of the applied load spectra and sequence effects of different amplitudes have been investigated. This document covers tubes of 4 to 8 mm thickness made by low-carbon or mild steel S355J2H. In general, it was found that the spectrum shape and the loading sequence have an influence on the service life. Depending on the shape of the spectrum, random tests tended to lead to shorter service lives than tests with block-loading sequences. An influence of overloads was also found for the tests with interspersed overloads. Typical maximum linear damage sums taken from recommendations and codes of 0.2 or sometimes 0.5 are exceeded for all spectra investigated and in some of the cases even significantly above 1.0. Transferability of the recommendations to component-type structures like tubular joints needs revision to lift its lightweight potential. Using stress concentration factors (SCF) from finite element analysis, typical strength values for the structural and effective notch stress concepts are checked. All joints investigated show a significantly higher strength compared to the IIW recommendations using the structural stress approach or compared to the DVS 0905 with the effective notch stress approach.

Experimental study on optimization of continuous steel box girder bridge deck

ABSTRACT In order to accurately optimize the structural parameters of steel bridge deck(OSD), an optimal design method of continuous steel box girder bridge deck based on response surface method is proposed. Optimization design process includes full scale model test, finite element analysis, response surface function fitting and design parameter optimization. The orthotropic steel bridge deck’s deck thickness, stiffener thickness, diaphragm thickness, stiffener height, and diaphragm opening form are chosen as independent variables, and the internal forces of important structural components discovered are used as dependent variables. Design-Expert software created a five-factor, three-level response surface test. A multivariate quadratic response surface regression model between structural parameters and target response values was developed after the objective function and constraint criteria were identified. Numerical theory’s variance analysis was used to find the best combination, and Design Expert software was used to confirm it to make sure the design value was accurate. The findings indicate that optimized structural parameters are trustworthy because the difference between the predicted value and the theoretical value is less than 5%. An orthotropic steel bridge deck’s structural parameters can be optimized using the response surface approach. It serves as a reference for subsequent steel bridge deck design and construction.

Fatigue tests on connections of hollow sections made of high‐strength steel with shape‐optimized gusset plates

AbstractStructures made of hollow sections are often used in the construction of steel bridges, agricultural machinery and trucks. Due to secondary bending moments and local stress concentrations at the connection between brace and chord these joints have a low fatigue strength. In case of high‐strength steels, a decisive fatigue design leads to larger wall thicknesses and dimensions of the hollow sections and thus to uneconomical constructions. In the course of the research project FOSTA P1442 truss joints of hollow sections made of high‐strength steels were reinforced by attached and plugged through gussets plates to increase the fatigue strength by relocating the most critical detail at the weld toe to areas subjected to lower stresses. At the University of Applied Sciences Munich, 35 large‐scale fatigue tests on hollow section K‐joints with differently shaped gusset plates were performed to verify the results of the Finite Element Analysis. In order to verify the applicability of the results to real structures, two trusses with a span width of 6 meters were tested. Based on the data of the experimental tests, a fatigue design recommendation for connections of hollow sections with gusset plates could be developed. Within this paper the set‐up and results of the fatigue tests are summarized.

EXPERIMENTAL AND NUMERICAL INVESTIGATION OF DOWEL STRIPS FOR LONGITUDINAL AND TRANSVERSE LOADING

AbstractA new field of application for dowel strips are orthotropic composite roadway slabs. In contrast to conventional composite steel bridge construction, the dowel strips create a two‐dimensional bond. As a result, they are not only exposed to longitudinal but also to transverse shear forces. Up to now, neither the load‐bearing capacity nor the load‐deformation behavior under transverse shear forces have been investigated. Furthermore, there are design related deviations from the current approval in form of a lower dowel distance. This paper presents two different types of push‐out tests, which provide new insights into small composite dowel strips under longitudinal and transverse loads. Based on these tests and numerical investigations, the effects of smaller dowel strips are analyzed and special features of the load transfer mechanism under transverse shear forces are highlighted. The investigations presented here were carried out as part of the AiF‐FOSTA research project P 1265 [1].

Construction Management and Installation Quality Control Strategy of Steel Bridges

At present, China’s bridges are mostly made of concrete, which contain a large amount of cement, sand and gravel and other materials, which can easily cause environmental pollution. At the same time, China’s total steel production continues to rank first in the world. The construction and development of steel bridges have sufficient basic support. At the same time, steel is more environmental-friendly than concrete, with higher strength, lower weight, and can reduce construction waste significantly, so the development of steel bridges has been on the rise. To optimize the application effect of steel structure bridges, it is necessary to analyze the construction management and installation quality control strategies of steel bridges for reference.

Investigations on the Shear Capacity of Stainless Steel for its Use in Steel and Composite Bridge Construction

AbstractThe paper deals with the shear capacity and the shear buckling behaviour of plates made of (lean) duplex stainless steel. For this purpose, twelve experimental tests on torsionally loaded square box girders were carried out to investigate the shear capacity. Two different materials and three different buckling slendernesses were investigated. An FE model was created and calibrated using the experimental results. Subsequently, a parameter study was carried out in order to be able to cover a larger buckling slenderness range. The experimental and numerical results were then compared with the specifications of EN 1993‐1‐4 and an assessment of the specifications is provided.

High‐cycle variable amplitude fatigue experiments and design framework for bridge welds with high‐frequency mechanical impact treatment

AbstractFatigue enhancement by way of high‐frequency mechanical impact (HFMI) treatment can enable effective design and construction of steel bridges. However, bridges may experience high and varying mean stresses, the effects of which are not covered today by any design recommendation or in the literature on HFMI‐treated joints. In this study, fatigue experiments were conducted with realistic in‐service bridge loading, which revealed the same high fatigue performance as for constant amplitude loading. The effect of mean stress in spectrum loading was quantified and a method to account for it in an equivalent manner is proposed. A design framework has been developed for design and engineering purposes.

PENGARUH KARAT TERHADAP KETANGGUHAN MARETIAL BAJA UNTUK JEMBATAN

Rust is a major problem in steel bridge construction because it has the potential to affect the integrity of the structure and is also an important consideration for inspection and maintenance programs. This study shows the results of laboratory tests on the effect of rust within 1 to 9 weeks on fracture toughness as one of the important mechanical properties of steel bridge elements. The specimens in this study were made of SM 490 type, steel commonly used for bridge construction. Rustless and rusted specimens were used with varying degrees of exposure after immersion in acid solution to simulate the rate of rust. The effect of rust rate on fracture toughness due to mass loss was studied. The fracture toughness of each specimen was monitored for those specimens with exposure periods of 1 week, 2 weeks, 3 weeks, 4 weeks, and 9 weeks to test their effect on toughness. The results of this study showed that there was no significant reduction in the rusting duration of 1 week, 2 weeks, 3 weeks, 4 weeks, and 9 weeks of fracture toughness. Rusting and testing activity for the long term is still ongoing and will be continued, as the results of this study greatly help bridge designers and asset managers to better model rust inspection and maintenance plans and assess the structural integrity of steel bridges affected by rust more accurately.

Investigation of the Fatigue Stress of Orthotropic Steel Decks Based on an Arch Bridge with the Application of the Arlequin Method.

Orthotropic steel decks are widely used in the construction of steel bridges. Although there are many fatigue-evaluation methods stipulated by codes, unexpected fatigue cracks are still detected in some bridges. To justify whether the local finite element model commonly used in fatigue investigations on orthotropic decks can correctly instruct engineering practices, the Arlequin framework is applied in this paper to determine the full fatigue stress under traffic loads. The convergence on and validity of this application for orthotropic decks are checked. Results show that the Arlequin model for deck-fatigue analysis established in this paper tends to be an efficient method for complete fatigue stress acquisition, whereby the vulnerable sites of orthotropic steel decks under traffic loads are defined. Vehicles near the flexible components, such as hangers or cables, can have adverse effects on the fatigue durability of decks. Additionally, the total number of vehicles and their arrangement concentration also affect fatigue performance. Complex traffic conditions cannot be fully loaded in local models. Regardless of the gross bridge mechanics and deck deformation, the fatigue stress range is underestimated by about 30–40%. Such a difference in fatigue assessment seems to explain the premature cracks observed in orthotropic steel decks.

Predicting the patch load resistance of stiffened plate girders using machine learning algorithms

In the incremental launching method employed for steel bridge construction, the girder is subjected to patch loading which occurs at the piers’ position. This loading significantly affects the girder resistance in the construction stage. Therefore, prediction of the girder resistance under this loading is important. This paper proposes a new approach for predicting the patch load resistance of stiffened plate girders using an extreme gradient boosting algorithm (XGBoost). A total of 170 experimental data on stiffened plate girders under patch loading collected from the literature serves as the training and testing data to build the predictive model. To demonstrate the efficiency of the proposed model, its predictions were compared with those obtained from other Machine Learning (ML) methods such as support vector machines (SVM), decision tree (DT), random forest (RF), adaptive boost (Adaboost), and deep learning (DL). The accuracy of the proposed model was validated against the existing equations taken from the design standards (EN-1993-1-5 and BS 5400) as well as existing formulae in the literature. The comparative results reveal that the proposed model provides better and more accurate predictions than the existing formulae.

Accelerated corrosion behavior of weathering steel Q345qDNH for bridge in industrial atmosphere

Weathering steel (WS) has an extensive use in steel bridge construction thanks to its satisfactory atmospheric corrosion resistance, low life cycle cost and good mechanical properties. In this paper, cyclic immersion corrosion experiment was carried out in simulated industrial atmospheric environment. The corrosion weight loss, macro morphology, rusting coat section, XRD and electrochemical characteristics of bridge weathering steel Q345qDNH and low alloy steel Q345qD were compared. The corrosion characteristics were identified and underlying corrosion inhibition mechanism of bridge weathering steel Q345qDNH were analyzed. The experiment and analysis results show that the rusting coat on the exterior of standard carbon steel is relatively loose and porous, and the main component is Fe3O4. The rusting coat of weathering steel is divided into internal and external layers under atmospheric corrosion, the outer rusting coat is loose primarily composed of γ – FeOOH and the inner rusting coat is uniform and dense, principally containing α – FeOOH. During the evolution of the rusting coat, the addition of trace alloy elements in weathering steel effectively promoted the transformation from γ – FeOOH to α – FeOOH, forming a more stable and condense inner rusting coat. It can potently isolate the corrosive medium from penetrating in and enhance the electrochemical corrosion resistance of rusting coat, so it possesses better corrosion resistance in atmospheric corrosion environment and has a promising application prospect in bridge engineering construction.

EFFECT OF WELDING HEAT INPUT ON THE CORROSION RATE OF CARBON STEEL MMA WELDING

AbstractSteel is one of materials which often used on steel construction, bridge construction, and high rise building construction. Construction using welding joint is expected able to withstand construction loads for a long time. After a while weldment will be exposed to corrosion that will be construction failure in turn. One of the most important parameter in welding is heat input, however it hasn’t obtain correlation between heat input and corrosion rate on MMA (Manual Metal Arch) weldment on mild steel. This paper aims to obtain correlation between heat input and corrosion rate of low carbon steel with MMA welding. The result was show that corrosion rate tend to decrease with adding of duration, where higher corrosion rate at heat input 0,8108 kJ/mm was 68,68 gm/m2 hr at duration 5 hour.

Innovations for the optimal use of weathering steel in steel and composite bridge construction

Innovations for the optimal use of weathering steel in steel and composite bridge construction

Slip‐resistant connections in hot‐dip galvanized steel bridge constructions

AbstractEconomic efficiency and sustainability in bridge construction are, in addition to the cost of new building, determined by the incurred maintenance costs. Hot‐dip galvanized bridge constructions can achieve a corrosion protection period in the magnitude of their lifetime (≥ 100 years). Hot‐dip galvanized steel structures are well established and state of the art for public and industrial buildings. Various research projects demonstrate hardly any losses on the fatigue strength compared to the non‐galvanized steel components. Welded site joints of hot‐dip galvanized components require a complex pre‐ and post‐treatment of the corrosion protection. Nevertheless, on‐site applied corrosion protection cannot reach the protection durability of a hot‐dip galvanizing. This technological restriction can be avoided by the use of hot‐dip galvanized bolted connections. Slip‐resistant pre‐stressed connections are proved successful in steel bridge construction. Major scientific investigations are not yet available for the use of slip‐resistant connections for hot‐dip galvanized joints. Technical and scientific foundations for the application of hot‐dip galvanized bolted connections in cyclically loaded steel and composite bridge constructions, based on the European standard for steel constructions, are investigated within the scope of a research project at the MPA. The provision of construction and design recommendations is the goal of this project.

Crane Lifting Optimization and Construction Monitoring in Steel Bridge Construction Project Based on BIM and UAV

Modular construction methods are adopted in many spatial and temporal limited projects. As the major equipment used in modular construction, the mobile crane affects the safety and efficiency of construction significantly. Currently, building information modeling (BIM) is widely adopted to improve the lifting operation planning of cranes. However, the inaccurate simulation of the dynamic construction environment makes those BIM‐based lifting operation planning methods unsuitable for land mobile cranes operation planning, such as in the overpass bridge construction project, which may cause several safety risks during the lifting process. Based on an overpass steel bridge construction project, this paper attempted to integrate the BIM and unmanned aerial vehicles (UAVs) to streamline lifting operation planning and construction monitoring. Specifically, in the preliminary stage, a level of development (LOD) 400 steel superstructure model was built and then divided into eighty sections. In addition, a three‐dimensional (3D) geology model of the as‐is construction site was modeled by UAV‐captured images. Then, a fusion model which contains the lifting modules models, the as‐is site model, and the crane model was gathered, based on which the collision detection was conducted by 4D crane operating path simulation. According to the results, three potential collisions were found and eliminated by lengthening the jib of the crane from 43.5 m to 46.5 m. Furthermore, the optimum crane location for lifting each steel structure was determined based on the 3D geology model. The study shows that the UAV is able to acquire geological information and then 3D simulates the real construction environment quickly and accurately. Furthermore, BIM and UAV have the potential to optimize the design and construction as well as the monitoring of bridge projects.

Steel Bridge Construction of Hong Kong–Zhuhai–Macao Bridge

The 55-km-long Hong Kong–Zhuhai–Macao Bridge (HZMB) is the world’s longest sea-crossing bridge, connecting Hong Kong with Zhuhai and Macao at the mouth of the Pearl River Estuary in China, comprising 22.9-km-long steel bridges. HZMB is the leading steel bridge in China, with top-level manufacturing and installation technology. This paper outlines the steel bridge construction experiences of HZMB to provide comparisons for the construction of other long sea-crossing steel bridges at home or abroad. The main considerations of construction constraints, scheme selection, structural and aesthetic design of HZMB are presented, and the following points related to new strategies in the steel bridge construction of HZMB are elaborated: (1) construction quality assurance, (2) automatic manufacturing technology, (3) large segment offshore installation, (4) eco-friendly paint (content limitation of volatile organic compounds) and new multifunctional inspection gantry, and (5) Guss Mastic Asphalt steel deck pavement system. The successful implementation of those strategies shows that the steel bridge construction of HZMB promotes improvement in the overall construction and management level of the Chinese bridge industry. The advanced experience of HZMB has opened up broad prospects for the design and construction of offshore bridge engineering in China.

Fatigue behavior of a riveted connection detail used in steel bridge construction

Fatigue behavior of a riveted connection detail used in steel bridge construction

Research on Standardized Structure and Construction Technology of Steel Truss Bridge with 40m Span

In recent years, China’s steel production has been greatly increased, so the ministry of communications strongly encourages the development of steel structure bridges, and steel truss bridges are suitable for medium and small span. Under this background, this paper analyzes, studies and designs the standardized structure of medium and small span steel truss bridge. According to the basic structure, design requirements and design calculation theory of steel truss bridge, the corresponding finite element models are established respectively, and the standardized design sizes of steel truss bridge simply supported 40m and continuous 3 × 40m are given. At the same time, based on the domestic and foreign small span steel bridge erection and construction control technology, select the overall hoisting construction method to simulate the steel truss bridge construction process, so as to each construction stage structure static performance and construction control are systematically analyzed. This paper presents the key points of controlling the construction stage of 40m span steel truss bridge, which provides theoretical support for accelerating the construction period of the bridge and ensuring the construction safety of the bridge.

THE LOST HERITAGE OF ROMAN IRON AND STEEL BRIDGES. VIRTUAL RECONSTRUCTION OF TWO CASE STUDIES

Abstract. In the second half of 19th century the city of Rome knew a period of great urban transformations: the Pope Pio IX and after, the government of the new Kingdom of Italy, strongly pushed the modernization of the ancient and underdeveloped city, trying to follow the examples of the main European capitals. One of the most relevant signs of that period was the construction of multiple iron and steel bridges along the Tiber, that were built to improve the crossing network guaranteed by the old masonry links. Different supporting systems were used and many experimental technologies for the Italian context were tested, representing a crucial phase for the settle of a design and an industrial know-how that was firstly imported from the most advanced countries of the Northern Europe. In the 20th century most of these connections were unfortunately replaced, losing this precious heritage which was strongly linked to the technological culture of the time. Garibaldi Bridge, still present but radically transformed, and Alari Bridge, completely demolished, have been accurately modelled thanks to the availability of appropriate archival documentation and on-site tests, applied following a proposed methodology. The virtual reconstruction of the two case studies permits to spread the knowledge of this lost heritage, to ease the divulgation of past technologies and to recover the unusual image of exposed iron and steel structures surrounded by the ancient panorama of the Eternal city.

Modeling of stress and strain states induced by torsion of straight rods with elliptical cross sections

Torsion of bars of various cross-section is of great practical utility in engineering, structural design and mechanical work. It is applied in machine construction, steel bridge or railway construction. Many publications can be found in literature that present the stress-strain analysis in the case of straight rods with constant profiles subjected to torsion. Most of these works were however directed to the case of rods with simple connected domains as cross sections. The present work uses a semi-inverse method which permits to determine general equations for stress-strain analysis in the case of rods having a multiple connected domain as cross section, subjected to torsion. For the present study, the general equations were customized for two particular cases that of an elliptical cross section and that of an elliptical ring.The determined analytical equations were implemented to a specific situation by aid of Mathcad software. This permitted to graphically represent the distribution of torsion stresses and cross-section deflection.