Seismic behavior of steel reinforced concrete column with welded studs subjected to combined action of compression-bending-shear-torsion

Abstract

This paper presents the seismic behavior of steel reinforced concrete (SRC) column with welded studs. Nine SRC columns, varying in stud position, stud spacing, stud length and stud layout, were tested under combined compression-bending-shear-torsion cyclic load. All specimens were subjected to bending-torsion failure with the characteristics of concrete crushing and X-shaped cracks. The fullness of hysteretic curves of bending moment and torsion moment showed that the torsional energy dissipation of the SRC columns was poor. The arrangement of studs at the flange could improve the seismic behavior of SRC columns, and decreasing the stud spacing and increasing the stud length could play an enhanced effect, but the effect of setting the studs at the web was not significant. For SRC columns subjected to torsion moment, a certain number of structural studs need to be added to enhance their torsional properties under the condition that the studs can resist bending moment. In addition, the strain distribution illustrated that the web of encased steel played a great role in resisting torsion, so the torsional bearing capacity of SRC columns was mainly controlled by the strength of the web. Based on the unified strength equation established in this paper, a calculation method of torsional bearing capacity of SRC columns, subjected to combined action of compression-bending-hear-torsion, was proposed.