Analysis of stress mechanism in a new prefabricated SRC composite column

Abstract

The superior seismic performance of prefabricated steel-concrete composite structures has recently become a major research focus in the earthquake engineering field. This study proposes an off-site precast steel reinforced concrete (PSRC) column base joint. This joint has a high bearing capacity, efficient assembly, and a fuse function for plastic deformation accumulation at the middle connection. Besides, multiple finite element models are built and calibrated based on the test results using ABAQUS. The research discusses the influence of various parameters on failure modes and seismic performance. The results indicated that the failure position is primarily concentrated in the middle connection, whereas the stress distribution differs within the middle connection. The axial compression ratio and the middle connection position height significantly affect the initial stiffness. The bearing capacity is considerably influenced by various parameters, excluding the thickness of the stiffening plate and cover plate. It is recommended to use an optimal axial compression ratio of 0.45 and a shear span ratio between 2.0 and 2.8 while controlling the stiffening and cover plate thicknesses between 10 and 16 mm. The shear mechanism of the PSRC column base joint mainly includes a steel plate shear wall mechanism and a T-shaped steel frame mechanism. The simplified bearing capacity model results for the proposed PSRC column base joint match well with the experimental and FEM results, and the calculation results are good.