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In the member states of the European Union the design of slender steel plates is covered by EN 1993-1-5:2006. One of the main application fields of EN 1993-1-5 are bridges where the design is dominated by slender plated elements. Aside of a general overview on EN 1993-1-5 this paper presents the main results of the European research project COMBRI which can be considered as stepping stone for a large number of research projects in the field of plate buckling and for a systematic development of EN 1993-1-5. The main outcomes are summarised and background information is given for a selected number of improved rules.

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This paper summarizes a recently completed research programme carried out at the University of Sydney on drive-in steel storage racks subjected to horizontal impact loads. Impact loads develop frequently during the normal operation of drive-in racks when the forklift truck strikes an upright on entering or leaving a bay, and may lead to local or global collapse. The collapse follows the bowing of the upright which may cause a pallet to drop off the supporting beam rails and initiate progressive collapse down through the bay and possibly into adjacent bays as well.
The research programme comprised full-scale tests on assemblies of a four-bay-wide racking system, tests on system components, the development of finite element models capable of predicting the behaviour of the system accurately, parametric studies of the strengths and stiffnesses of steel storage racks, the development of a simple mechanical model for understanding the dynamic behaviour of the system during impact and a reliability analysis for deriving equations for the design impact loads and associated load factors.
The purpose of the paper is to give an overview of the methodology adapted for the research programme and to present the main findings and final outcome of the research.

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Single-storey steel buildings in Canada are generally designed with a steel roof deck diaphragm to resist and transfer lateral loads to the vertical bracing system. Current Canadian seismic design provisions for these buildings are reviewed here with a focus on the design of the roof diaphragms. An equivalent static analysis method is generally used for these structures and comprehensive capacity design principles are applied to achieve a proper strength hierarchy in order to develop the intended yielding mechanism along the lateral load path. The method is illustrated with the help of a numerical example. The influence of roof diaphragm in-plane flexibility on the dynamic seismic response is discussed.

Experimental investigations and parametric finite element analyses show that the moment-rotation characteristic of sandwich panels providing support against the lateral torsional buckling of beams subjected to gravity loading can be represented as tri-linear. Formulae for calculating the parameters of this characteristic are given for different types of beam combined with sandwich panels for roofs and walls. According to available design codes, the torsional restraint coefficient for rotational stiffness cϑ required for design against lateral torsional buckling of beams is governed by the rotational stiffness cϑA of the connection, which can be obtained from the characteristic mentioned as the secant stiffness for all common types of sandwich panel and different types of structural arrangement. These values allow the maximum spans of beams to be increased and help to improve the economy of lightweight structures.

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Steel construction is becoming increasingly popular in Southern Africa. Selected case studies of steel structures are presented and discussed here to support this statement. The discussion entails the extent to which the design of steel structures facilitates ease of construction. It is recognized that steel has been with us for some time and that most of the world’s spectacular bridges have taken advantage of the relative lightness of the material for long spans. More recently, high-rise steel-framed buildings have further demonstrated the versatility of steel. This is happening despite the fact that throughout its history, the steel industry has been dogged by high production costs, almost inevitably resulting in heavily subsidized steel. Dramatic improvements in process technology and a better understanding of the behaviour of structural steel coupled with an extensive market programme are now putting structural steel in its rightful place.

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NASC - The Steel Conference
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ISOPE 2012 - International Offshore (Ocean) and Polar Engineering Conference
IABMAS 2012 - 6th International Conference on Bridge Maintenance, Safety and Management
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Steel Structures and Bridges 2012

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Rather than treating final publication of EC3 and EC4 as signalling that research into the behaviour and design of structural steelwork should now reduce because justification is less, the argument is made that there may well be an increasing need as the discovery of shortcomings, limitations and omissions in those Codes provides another, potentially very fertile, source of new challenges. Several illustrations of different types of “opportunities for improvement” are provided in support of this contention.

The objective of this paper is to provide a brief review of recent (over approximately the last five years) advances in the application, analysis and design of cold-formed steel structures. Attention here is focused on load-bearing cold-formed steel structures; as opposed to secondary systems, curtain walls, etc. Cold-formed steel applications continue to advance in three primary categories: framing, metal buildings, and racks. Examples largely derived from the author’s experiences in North America are used to illustrate the applications. The behaviour of cold-formed steel structures can be complicated due to the thin-walled nature of the sections; thus, analysis advances are required. Recent work in Generalized Beam Theory and the constrained Finite Strip Method demonstrate that, at least when it comes to thin-walled members, significant advances in structural analysis are still possible and desirable. Design of cold-formed steel structures continues to see significant improvements and refinements. Recent efforts related to the Direct Strength Method of design are highlighted, including novel extensions from the member to the system level. Finally, similar to many other areas of structural engineering, seismic engineering has motivated notable advances in applications, analysis, and design. For cold-formed steel structures these advances are reviewed to demonstrate current progress and future directions in this important area.

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The main part of the bridge is a basket handle type tied-arch bridge. The geometrical size, structural solutions and erection method of the bridge required preliminary research and advanced design methodology. This paper gives a general outline about the construction of the steel structure of the arch bridge and emphasizes some of the design aspects.

The studied joint configuration is illustrated in Fig. 1. Two different transfer areas may be distinguished. The upper area consists of a reinforced concrete slab where the longitudinal reinforcement is anchored in the reinforced concrete wall. The wall and the slab were concreted at different times and therefore, no shear is assumed to be transferred between these members. Any friction is neglected. Thus, only tension is transferred through this part of the joint. At the bottom area, the steel beam sits in a steel bracket welded to an anchor plate which is fastened the reinforced concrete wall. The fixation between anchor plate and wall is achieved by headed studs welded to the plate. On the outside of the steel bracket, a plate is welded creating a “nose” which avoids the slip of the beam out of the steel bracket. The end-plate of the steel beam is used for this propose. This end-plate transmits the shear load to the steel bracket. Finally, compression is transferred to the reinforced concrete wall using a contact plate between end-plate and anchor plate. The flux of loads is schematically represented in Fig. 2 for a hogging bending moment.

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Recent events such as natural catastrophes or terrorism attacks have highlighted the necessity to ensure the structural integrity of buildings under an exceptional event. According to the Eurocodes and some different other national design codes, the structural integrity of civil engineering structures should be ensured through appropriate measures but, in most cases, no precise practical guidelines on how to achieve this goal are provided.
At the University of Liège, the robustness of building frames is investigated following the so-called “alternative load path method”, with the final objective to propose design requirements to mitigate the risk of progressive collapse considering the conventional scenario “loss of a column” further to an unspecified event. In particular, a complete analytical procedure has been developed for the verification of the robustness of steel or composite plane frames. For sake of simplicity, these first works have been based on the assumption that the dynamic effects linked to the column loss were limited and could therefore be neglected. More recently, complementary works have been carried out with the objective to address the dynamic effects. Besides, the extension of the static procedure to actual 3D frames is under investigation in Liège. The present paper gives a global overview of the ongoing researches in the field of robustness at the University of Liège and, in particular, the global strategy aiming at deriving design requirements is detailed.

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A new type of seismic resistant structural steel braced-frame system is introduced that employs controlled rocking, elastic post tensioning, and replaceable fuses to resist earthquake shaking with limited structural damage. Through the use of capacity design principles, inelastic energy dissipation is confined to replaceable fuses while the controlled rocking and elastic post tensioning provide self-centering action to eliminate residual drift. Quasi-static cyclic tests and dynamic shake table tests of large-scale specimens confirm that the system can sustain extreme earthquake ground shaking with story drift ratios up to 3 % without structural damage. Owing to the well-defined rocking mechanism, analysis and design of the system is straightforward. Work is ongoing to develop design criteria and guidelines to facilitate practical implementation of these system in building design and construction.