Model updating and seismic response of a super tall building in Shanghai

Abstract

The Shanghai Tower is presently the tallest structure in China and one of the super tall buildings in the world. To get a quick and direct insight into the overall dynamic behavior of this complex structure, a lumped-mass finite element model based on macro beam theory was developed. Next, an in-depth sensitivity analysis was performed on this baseline model and model updating was conducted by using modal properties obtained from a full-scale field test of this building in its final stage of construction. The difference of the first nine frequencies was reduced from 27% to 4% after updating, and modal assurance criterion value was improved from 73% to 87%. Time history analyses under two severe seismic events were conducted on both the baseline and updated models. The maximum story drift from the updated model were 40% higher than that from the baseline model, demonstrating the significant influence of model updating on its seismic performance. The framework of model updating by simplified updated model for super tall buildings described in this study provides an efficient way to predict their seismic responses, and the outputs are reliable for wide range of applications in the area of long-term heath monitoring and seismic retrofit.