Shaking‐table test results of a full‐scale free‐standing building with base sliding and rocking

Abstract

This paper present results of shaking-table tests conducted in 2015 and 2018 on a free-standing base sliding and rocking system, which allows sliding and uplifting. A full-scale 10-story reinforced concrete (RC) building equipped with cast iron plates on the bottom surface of the grade beams was used as a specimen for 2015 and 2018 experiments. In 2018, the static friction coefficients of the specimen were 0.48 and 0.49, which was higher than that of the rustproofed specimens in 2015. In the experiments of 2015 and 2018, the normalized base shear (NBS) values when the sliding length of the building reached ≥1 mm were 0.0035-0.1795 and 0.1744-0.2748, respectively. In the shaking-table test corresponding to moderate earthquake motions, the 2018 specimen showed almost no lateral movement, whereas the 2015 specimen moved laterally. Therefore, more seismic energy was input into the specimen, and the maximum interstory drift ratio of the 2018 specimen was larger than that of the 2015 specimen. However, when the 50% amplitude excitation results of the 2015 seismic structural system are compared with those of the 2018 free-standing structural system, the 2018 results are approximately 0.57 times smaller. Thus, a free-standing structural system with cast iron plates to reduce earthquake energy could reduce damage to buildings. The 2018 specimen satisfies the concept of a free-standing base sliding and rocking system that does not move laterally during small to moderate earthquake motions but moves laterally during strong earthquake motions to suppress structural damage.