Experimental Study on Circular RC Bridge Columns under Combined Cyclic Flexural and Torsional Loadings

Abstract

Complex flexural, shear and torsion failure of reinforced concrete (RC) bridge columns for skewed and curved bridges will be taken place during seismic excitation. An experimental investigation on the seismic performance of RC bridge columns subjected to combined cyclic bending and torsional loading was carried out. Five test models of circular RC bridge columns were tested under various loading conditions: cyclic uniaxial bending, cyclic torsion, and combined cyclic torsion and cyclic uniaxial bending. Several combinations of cyclic bending and cyclic torsion were applied to evaluate the interaction between torsion and flexural capacity of columns. The results reveal that: (1) the flexural capacity in flexure decreases when the torsion increases; (2) the torsional capacity in torsion decreases when the bending moment increases under combined bending and torsion; and (3) the damage tends to occur upward outside the flexural plastic hinge region when the level of applied cyclic torsion increases.