Seismic behavior of terminal stirrup-confined concrete-filled elliptical steel tube columns: Experimental investigation

As a new member of concrete-filled steel tube (CFT) structural families, elliptical tubes (CFETs) have great potential to be used as piers and columns in bridges airport terminals because its low flow resistance coefficient reasonable distribution major–minor axis. Hence, the main objective this paper presents an experimental investigation on seismic behavior terminal stirrup-confined (TS-CFET) columns. Pseudo-static tests were tested investigate performance TS-CFET columns, including 3 (CFET) 11 Those key parameters varied experiments included stirrups, height stirrup region, equivalent ratio, loading direction, slenderness ratio axial load ratio. Then, based results, complete curves analysis (P) vs. deflection (Δ) hysteretic analyzed detail, failure modes composite action between core concrete discussed clarified. Furthermore, six indexes employed quantify effect parameters. The results indicated that using stirrups CFET can directly confine concrete, then considerably enhance especially under higher With increase energy dissipation capacity increased, while displacement ductility decreased. major axis was obviously superior minor loading. Additionally, had significant influence ultimate bearing capacity, stiffness