Numerical studies of deep concrete coupling beams retrofitted with a laterally restrained steel plate

Abstract

Existing deep reinforced concrete (RC) coupling beams with low shear span ratios and conventionally reinforced shear stirrups tend to fail in a brittle manner with limited ductility and deformability under reversed cyclic loading. Experimental studies have shown that a laterally restrained steel plate (LRSP) can be used to retrofit existing deep RC coupling beams. In this way, the deformability and energy dissipation of the retrofitted beams are greatly enhanced. In this paper, a nonlinear finite element package ABAQUS was used to model the behaviour of plate buckling by considering the plate's geometric and material nonlinearity. The effects of adding lateral restraints and the influence of tension field actions on the shear carrying capacity of the steel plate were quantified. The numerical results confirm the effectiveness of adding lateral restraints. By using the nonlinear finite element package ATENA, the overall behaviour of LRSP-retrofitted coupling beams was simulated. To obtain accurate results, the effects of plate buckling and bolt slipping were incorporated into the simulations. Finally, the effect of the plate's thickness and the bolt's stiffness on the performance of LRSP coupling beams was investigated in detail.