Risk-informed design for structural robustress in ordinary building projects

Abstract

Robustness has become a requirement in the modern building codes. Despite significant theoretical and methodical progress in the recent years, structural robustness still has remained vague in its interpretation, evaluation and regulations. After the introduction of Eurocode in Sweden in 2011, the structural engineering community has had significant difficulties to apply the present rules, mainly because building practices are different from those in UK. The prescriptive tie requirements in Eurocode seem not to be technically suitable method in Sweden. In this thesis, the feasibility of a risk-informed design approach for structural robustness has been examined for an actual case. The analysis has shown that in the ordinary buildings, the Eurocode requirements for structural robustness could simply be replaced by mitigation measures and independent check of a third party. Almost all construction failures in Sweden are attributed to gross errors in the building processes, therefore robustness is best controlled by quality control. Engineering judgement plays a major role in the proposed approach. According to this method, design for robustness cannot be transferred into precise and generic rules as desired by structural engineers and authorities. It highly depends on specific properties of the building in a certain project.