Employing Nonlinear Response History Analysis of ASCE 7-16 on a Benchmark Tall Building

Abstract

ASCE 7-16 has provided a comprehensive platform for the performance-based design of tall buildings. The core of the procedure is based on nonlinear response history analysis of the structure subjected to recorded or simulated ground motions. This study investigates consistency in the ASCE 7-16 requirements regarding the use of different types of ground motions. For this purpose performance of a benchmark tall building subjected to recorded and different types of spectrally matched ground motions is investigated. Application of ASCE 7-16 procedure, which is also adopted by the Los Angeles Tall Building Structural Design Council (LATBSDC) for amplitude scaling on tall buildings, results in unrealistically large scale factors. As expected, this large scale factor leads to a very conservative estimate of local and global demands by scaled recorded ground motions compared with spectrally matched ones. Recorded ground motions intrinsically cause large variation in engineering demand parameters (EDP), which is significantly magnified by large scale factors. The results are, a large ratio of maximum to mean response and control of the design process by maximum EDPs rather than mean values. Interestingly, capacities associated with maximum EDPs are vaguely defined in the code, partially due to the lack of knowledge on the elements actual response. It is also found that estimates of EDPs by different spectrally matched types of ground motions could be significantly different.

Keywords

• nonlinear response history analysis
• amplitude scaling
• spectral matching
• scale factor
• performance-based design