During the lifetime of a building, the highest risk is in the construction phase. The collapse of scaffolding systems occurs quite often with considerable accidents reported. This paper studies the major flaws or imperfections sequences that lead more easily to the collapse of a scaffolding system. The study has been focused in three different types of steel scaffolding systems: joint tubes, multidirectional and prefabricated systems, which are the most commonly used in construction. Diverse load tests on these different types of steel scaffolding systems have been made with commercially available software. The analysis has considered building imperfections, diverse base boundary conditions, effects of lateral restraint arrangement and different load distributions. Finally, the study propose an empirical formula to determine the critical load of a steel scaffolding system using the typology of the scaffolding system, the number of story levels and the different boundary conditions.Outgoin
