Seismic behaviour of flat connections between steel-plate composite (SC) walls and reinforced concrete (RC) walls

Abstract

The steel-plate composite (SC) wall has been a competitive substitute for reinforced concrete (RC) wall in nuclear power plants and small modular reactors. As essential parts of the structures, the joints and connections in various shapes deserve attentions, in which the seismic behavior of flat connection between SC wall and RC wall has not been adequately studied. In this paper, four large-scale flat connections with longitudinal rebars of RC walls inserted into SC walls were tested under cyclic out-of-plane loading. Test parameters involved shear-span ratios and construction details. For specimens with small shear-span ratios, the role of shear lugs passing through the interface between SC wall and RC wall was studied. For specimens with large shear-span ratios, the necessity of mechanical splices at the ends of the inserted longitudinal rebars was concerned. The failure modes, load-strain curves and load-displacement responses of test specimens were documented. A finite element model (FEM) simulating the behavior of the test specimens using ABAQUS was established for additional insights. Based on the results, the effects of the test parameters were analyzed in detail, the load-transfer mechanism of out-of-plane bending moment was illustrated. Since the shear or flexural failure on RC wall was observed in the specimens, the design equations for the nominal shear and flexural strength of RC walls were evaluated.