Advanced analysis as a new dimension for structural steel design

As an alternative to the prescriptive design based on individual member capacity check, performance- based design by direct simulation of structural system behaviour under ultimate loads is developed, both in concept and in computer implementation. The method has been proposed as an alternative design against the conventional prescriptive design using equations in codes with somewhat unreliable assumptions. This paper discusses the implementation of the method to ultimate design of a benchmark plane frame and a stadium constructed for the East Asian Game 2005 in Macau. The results show the advantages of the method in efficiency, economy and safety. The approach represents a new design practice for engineers in the 21st century. This practical advanced analysis will result in a more uniform reliability and safety for the designed frames such that redundant members will not be over-designed and key members under-designed. Research along the line of more accurate simulation should be carried out in future rather than refining the prescriptive member-based design formulae. Although general purpose finite element packages developed decades ago are, in principle, able to design steel structures by non-linear analysis using beam-column and shell elements, their daily application to civil engineering structures is impractical as many design code requirements cannot be simulated directly and automatically.