Comparison and Selection of Ground Motion Intensity Measures for Seismic Design of Super High-Rise Buildings

Abstract

Ground motion intensity measures ( IMs) are an important basis of structural seismic design. Extensive research has been conducted on the selection of IMs for building structures with fundamental periods shorter than 6 s. However, minimal work has been performed for super high-rise buildings whose fundamental periods are much longer than 6 s. To fill the gap in this research area, this paper aims to develop a simplified analytical model for super high-rise buildings based on the flexural-shear coupled beam model. The variation in correlation and dispersion between different IMs is evaluated and the structural seismic response demand measures ( DMs) are analyzed for different structural fundamental periods. Subsequently, rational IMs for the seismic design of super high-rise buildings are suggested. In addition, the influence of different flexural and shear stiffness ratios, α0, on the selection of an IM for super high-rise buildings is also discussed. Finally, a series of incremental dynamic analyses (IDA) of the Shanghai Tower, with a total height of approximately 632 m, is performed to verify the rationality of using different IMs for super high-rise buildings. The numerical results indicate that with a minimum dispersion, the peak ground velocity (PGV) has a better correlation to the story drift ratio than any other IMs. While considering structural nonlinearity, PGV still yields the minimum coefficient of variation in the collapse analysis of the actual super high-rise building. It is therefore recommended that PGV be used as an IM for the seismic design of super high-rise buildings.