Full-Scale Shaking Table Tests on a Resilient Dual Lateral System: First-Story-Rocking System With Gravity Frame

Abstract

In this paper, a first-story-rocking system (FSRS) with gravity frame which is a seismic resilient dual lateral system was investigated. Among them, rocking frame with bilinear elastic rocking is expected to protect the upper moment resisting stories through first story rocking; Gravity frame with low-damage joints served as a seismic resilient component that collaborates with rocking frames to optimize global stability and control the maximum displacement. As a part of the RObust BUilding SysTem (ROBUST) collaborative China-New Zealand program, a full-scale 3-story FSRS with gravity frame was designed. A series of shaking table tests were conducted to evaluate the dynamic behavior and seismic performance of the FSRS with gravity frame. The test results indicated that the tested building exhibited a longer instantaneous period under stronger excitations while the fundamental period identified by the white noise remained constant. The maximum inter-story drift ratio satisfied the limit of the current Chinese code for seismic design and the residual displacement was negligible. Horizontal vibration of the upper stories was well controlled, benefiting from the first-story rocking motion. Moreover, the restraining effect of the composite floor and gravity frame played a crucial role in mitigating the inter-story drift concentration in the first rocking story and the torsional response in the upper stories. The experimental results not only validated the expected excellent seismic performance of the resilient dual lateral system but also provided benchmark full-scale data for further analyses of numerical models and design methods.