Cyclic behavior of self-slitting squat composite shear walls with concrete-filled steel tubes: Experiment

Abstract

To improve the deformation capacity of low-rise shear walls, an alternative approach of self-slitting squat composite shear wall with concrete-filled steel tubular columns (SSLSST) was proposed by the authors. This paper presents the experimental results of five SSLSST specimens subjected to cyclic loading, experimental parameters included steel tube thickness (ts), spacing of transverse reinforcement (S), axial compression ratio (n), and shear stud arrangement of inner steel tube. The results showed that owing to weakened effects of both horizontal anchorage to concrete and vertical shear resistance, the self-slit occurred in the SSLSST specimen with half-section shear studs of inner steel tube; SSLSST specimens maintained integrality to resist lateral force like the normal shear wall before the yielding status; with the lateral deformation increasing, the SSLSST specimens were divided into three independent column-type segments to jointly resist both lateral and compressive forces, and the seismic damage mainly concentrated within the slits, resulting in the seismic damage of the whole shear wall body was reduced. Increasing both S and ts can not only greatly improved the seismic resistance and ductility but also reduced the seismic damage and post-earthquake residual deformation (PERD). As expected, high n was not beneficial for the ductility ratio, energy dissipation, and PERD. Generally, the proposed SSLSST showed slight seismic damage, good seismic resistance capacity, ductility, and self-centering ability. Therefore, it is worthy to promote this new type of low-rise shear wall system to actual engineering.