Performance-based seismic design method of stacked modular steel building based on three-dimensional seismic isolation

Abstract

Stacked modular steel building (SMSB) is widely used in China due to their rapid assembly, cost-effectiveness, and environmental benefits. However, their seismic performance is often poor due to discontinuous structural configurations. Seismic isolation technology, particularly the air spring-lead rubber bearing (AS-LRB) developed by the authors, offers a promising solution to enhance SMSB resilience. Despite its potential, the application of AS-LRB is limited by the lack of a systematic calculation method for performance parameters and a performance-based seismic design (PBSD) framework for SMSB. In this study, the construction and performance of the AS-LRB are briefly introduced, a calculation method for determining its performance parameters is derived, and a PBSD method for SMSBs based on the AS-LRB seismic isolation device is proposed in conjunction with the Chinese standard (GB/T 51408–2021), which mainly considers target period ratio (TPR) and design transmission ratio (DTR). To verify the effectiveness of the PBSD method, a four-story, three-span SMSB was designed using the PBSD method with AS-LRB, the isolation performance of SMSB was analyzed, and several calculations were performed to determine the TPR and DTR under different seismic performance objective (SPO). Results indicate that the calculation method can accurately obtain the performance parameters of the AS-LRB, the PBSD method based on AS-LRB for SMSB can achieve the expected SPO, and the isolated SMSB exhibits a better isolation effect. Furthermore, TPR and DTR with different SPO were obtained to provide reference values for the design of SMSB.