CHUNG-CHE CHOULin, Huang-ZuoHuang-ZuoLinCórdova, AlvaroAlvaroCórdovaChen, Jian-MingJian-MingChenChou, Yen-HsunYen-HsunChouChao, Shu-HsienShu-HsienChaoChao, Shih-HoShih-HoChaoTsampras, GeorgiosGeorgiosTsamprasUang, Chia-MingChia-MingUangChung, Hsin-YangHsin-YangChungHu, Hsuan-TehHsuan-TehHuLoh, Chin-HsiungChin-HsiungLoh2026-03-122026-03-122024https://www.scopus.com/record/display.uri?eid=2-s2.0-105027892765&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/736251AISC 341-22 (2022) is overly conservative on the width-thickness requirement for steel highly ductile built-up box columns, particularly in the buckling-restrained braced frame (BRBF). This study was aimed to assess the seismic performance of moderately ductile built-up box columns in a 3-story steel dual building system, which was composed of a special moment frame (SMF) and a BRBF. The effect of slab sliding on the floor acceleration reduction was also studied. Two test phases were conducted on the specimen: (1) the slab can slide relative to the frame specimen in phase 1, and (2) a nearly-rigid connection between the slab and the frame is adopted for investigating the seismic response of built-up box columns and all-steel sandwiched buckling restrained braces (SBRBs) in phase 2. A near-fault ground motion, recorded in the September 18th, 2022 Chihshang Earthquake, Taiwan was used as an input motion. In phase 1, the slab sliding was effective in reducing the floor acceleration up to 25% compared to a conventional frame with a rigid slab system. In phase 2, the maximum interstory drift angle of the frame was 0.045 rad without local buckling at the column base, and the maximum core strain of the first-story SBRB was 2.5%. Post-earthquake tests were conducted on the first-story SBRB, removed from the frame specimen after 17 shake table tests, showing high-mode buckling of the core plate near both ends of the restraining members, causing minor strength increase.false2022 Chihshang Earthquakemoderately ductile built-up box columnSandwiched buckling restrained braceshake table testsliding slabconference paper2-s2.0-105027892765