University of Trento University IUAV of Venezia Yufan Huang SEISMIC BEHAVIOR OF CONCRETE FILLED STEEL TUBULAR BUILT-UP COLUMNS Advisor: Prof. Enzo Siviero Università IUAV di Venezia, Venice, Italy Co-Advisors: Prof. Bruno Briseghella, Prof. Baochun Chen Fuzhou University, Fuzhou, China Prof. Tobia Zordan Tongji University, Shanghai, China 2015