An experimental program and associated numerical analysis were undertaken to study the shear-lag effect in round hollow structural section (HSS) tension members that are welded to gusset plates at their ends. The connection is made by slotting the tube longitudinally, inserting the gusset plate, and then placing longitudinal fillet welds at the tube-gusset interface. A total of nine specimens with three different tube sizes (HSS 102 × 6.4, HSS 102 × 4.8, and HSS 219 × 8.0) and various weld lengths were tested in the program. Most of the specimens failed by fracture of the tube somewhere between the two gusset plates, and there was considerable ductility prior to fracture. Most importantly, there was no reduction in the effective net area for the tested specimens, even with a weld length as little as 80% of the distance between the welds. Numerical analyses of the connections were carried out using an elastoplastic model and measured material properties. The studies showed that the restraint provided by the gusset plate at the slotted end effectively increases the load-carrying capacity of the tube as compared with that of the unrestrained portion of the member. In the analysis, fracture is assumed to have occurred when the equivalent plastic strain reaches a critical value. The test results are discussed in light of the requirements in the Canadian standard for design of steel structures.Résumé : Un programme expérimental accompagné d'une analyse numérique a été entrepris pour étudier l'effet du retard de cisaillement dans les membrures de tension de section structurelle creuse ronde (SSC), qui sont soudées à leurs extrémités à des plaques gousset. Pour faire la jonction, le tube est fendu dans la longueur, la plaque de gousset est insérée et des bandes de soudures longitudinales sont placées à l'interface tube-gousset. Un total de neuf spécimens de trois grandeurs de tube différentes (SSC 102 × 6.4, SSC 102 × 4.8 et SSC 219 × 8.0) et de longueurs de soudure diverses, a été examiné dans le programme. La plupart des spécimens se sont rompues par fracture du tube quelquepart entre les deux plaques gousset et il y avait une ductilité considérable avant la fracture. Le plus important, c'est qu'il n'y avait pas de réduction dans la surface nette efficace des spécimens examinés, même avec une longueur de soudure aussi petite que 80% de la distance entre les soudures. Des analyses numériques des jonctions ont été effectuées en utilisant un modèle élasto-plastique et des propriétés de materiau mesurées. Les études ont montré que la contrainte fournie par la plaque gousset au bout de la fente augmente efficacement la capacité de port-charge du tube, comparée à la portion non-restreinte du membre. Dans l'analyse, la fracture est supposée avoir eu lieu lorsque la contrainte plastique atteind une valeur critique. Les résultats des tests sont discutés à la lumière des exigences du standard Canadien de conception de structures en acier.

Numerous structural monitoring systems have been developed and installed in the field to collect information on the performance and behaviour of civil engineering structures and systems, such as buildings and bridges. The processing and analysis of large datasets collected from continuous monitoring systems often require a significant amount of time and effort. In order to accelerate the processing of these continuous monitoring data and to facilitate more rapid data analysis, and more timely interpretation and use of the results, a real-time data processing and analysis application platform has been developed which encompasses all aspects of data manipulation. This application platform consists of data processing, analysis and visualization modules, all integrated through graphical user interfaces (GUIs). The applications are designed and adapted to run in a real-time mode by automatically sorting incoming data and re-directing it to the processing and animation modules for graphic display of bridge displacements and motion in near real-time, as limited by the network speed. With this capability, after the occurrence of extreme events such as windstorms, earthquakes or ship impacts, bridge responses and condition of the facility can be assessed in a timely manner for decision support of its operation. The research opportunities that can be explored using the computer tool applications presented in this paper are illustrated by a discussion of recent research results.

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Spray-on fire protection is widely used in protecting building members, such as beams, against fire. As this protective coating may be damaged during the service life of the beams, it is essential that the effect of this damage on the fire resistance of a steel beam be understood. A numerical study has been conducted to investigate the reduction in the cross-section moment capacity of protected steel beams exposed to the ISO 834 standard fire due to partial loss of spray-on fire protection. Hot-rolled I-shape steel beams according to CAN/CSA-G40.20/ G40.21-98 specifications are used in this study. Results of the study indicate that the reduction of cross-section moment capacity due to the partial loss of protection strongly depends on the area of the protection damage. The reduction of crosssection moment capacity is also affected by several other factors, such as damage shape, damage location, damage penetration, and the weight and depth of the steel section.

This paper describes a multi-year PRCI research program that investigated the local buckling (or wrinkling) of onshore pipelines with metal-loss corrosion. The dependence of local buckling resistance on wall thickness suggests that metal-loss defects will considerably reduce such resistance. Due to the lack of experimental data, overly conservative assumptions such as a uniform wall thickness reduction over the entire pipe circumference based on the defect depth have been used in practice. The objective of this research work was to develop local buckling criteria for pipelines with corrosion defects. The work related to local buckling was carried out in three phases by C-FER and the University of Alberta. The first phase included a comprehensive finite element analysis to evaluate the influence of various corrosion defect features and to rank key parameters. Based on the outcome of Phase 1 work, a test matrix was developed and ten full-scale tests were carried out in Phase 2 to collect data for model verification. In Phase 3, over 150 parametric cases were analyzed using finite element models to develop assessment criteria for maximum moment and compressive strain limit. Each criterion includes a set of partial safety factors that were calibrated to meet target reliabilities selected based on recent research related to pipeline code development. The proposed criteria were applied to in-service pipeline examples with general corrosion features to estimate the remaining load-carrying capacity and to assess the conservatism of current practice.