Enhancement of structural analysis of multi-storey buildings by integrating non-structural components into structural system

© 2010 Dr. Bing LiIn the last few decades there has been an enormous increase in the number of high-rise buildings worldwide. Current Australian high-rise building design practice is to assume that the structural skeleton of a building provides resistance to any lateral forces that might occur. The overall design of high-rise buildings is usually dominated by serviceability limit state considerations rather than the ultimate limit state factors. Various structural forms and materials have been developed and adopted in the construction of high-rise buildings. The structural response depends on the structural form and materials utilised and also on the interaction between structural components and non-structural components for that buildings are widely recognised as a complex assemblage of both structural skeleton and non-structural components (Su et al. 2005). The lateral performance of high-rise buildings is complex because of the conflicting requirements of diverse (structural and non-structural) building systems (Hutchinson et. al. 2006). There is a scope to improve the serviceability limit state design requirements over the traditional approach. It is discovered that by integrating non-structural components into the structural analysis, building performance differs significantly. From the analyses in this study, when including different non-structural components in the structural analysis, the total stiffness of the building is significantly increased, to more than 50%, depending on the key influencing factors, which are discussed in this study: quantity, location, and connection properties assigned to the non-structural components. It is also noticed that the natural frequencies of the structure change when different non-structural components are included in the analysis. In terms of the stress distribution, by including non-structural components in the structural analysis, the bending moment and shear force distributed in the structural components, such as columns, change accordingly. These changes are related to their relevant locations to the specific non-structural components. The damage level of different non-structural components was also assessed. The maximum allowable structural movements defined by the Australian Standard were applied to the individual non-structural component. It is concluded that if not being delicately isolated from the primary structure, the precast concrete infill panels will not be able to accommodate the amount of stress transferred from the primary structure. Based on the results obtained from this study, it is concluded that integrating non-structural components into the structural analysis has significant influence on the serviceability of the overall structural system. Damages to the non-structural components caused by the interactions between the primary structure and the non-structural components are also remarkable, even if the whole building system is under service loads. Consequently, the structural analysis method adopted by the current design practice is suggested to be updated