Normal Section Bearing Capacity And Antiseismic Performance Analysis Of Column Reinforced By Addition Wing-wall

A lot of frame structures were damaged by high earthquake intensity in Wenchuan earthquake. For those columns, the damage were caused by insufficient stiffness. The reinforcement methods of damaged buildings were chose to get economic benefit depending on their own damage mechanism. According to the standard, the damaged columns in frame structures as a result of insufficient stiffness could be reinforced by additional wing wall reinforcement method. But, the research on the reinforcement of frame by wing wall was few. So in this paper, the load-bearing capacity of normal section and analysis on seismic behaviors of specially shaped columns as a result of additional wing wall method were analyzed.In the standard, the specially shaped columns were considered as overall eccentric component. As the direction angle, the eccentric compression analysis between specially shaped columns and rectangle columns were different. In the paper, the different specially shaped columns were formed by computer programming. In the way, the N-M curves of different specially shaped columns under different direction angle were got. At the same time, the Mx—My curves under different the axial compression ratio and M—φcurves were got. Based on the curves, the special-shaped cross-section columns had three kinds of failure modes: tensile damage,compression damage and boundaries damage as the same as rectangular eccentric compression component. The direction angle had bigger effect in the specially shaped columns who had a symmetry axis than those had no symmetry axis. The axial compression ratio had relatively bigger effect on the Mx—My curves of different abnormal cross sections. When the axial compression ratio was 0.5 to 0.6, the envelope area of Mx—My curves were biggest, the bending strength were the better.After reinforcement, the ductility of columns directly related to the seismic performance. In this paper, due to limited experimental condition, all kinds of special-shaped cross-section were analyzed by large-scale finite element analysis software ANSYS. The results showed that, considering the slippage between rebar and concrete and the degradation of concrete stiffness, ANSYS could simulate the mechanical properties of columns under low cycle reciprocating motion. By comparing the hysteretic curves and skeleton-frame curves under different axial compression ratio, the result showed that the bearing capacity increased obviously but the ductility reduced after wing wall reinforcement. The location of the additional wing walls had little effect on the bearing capacity of the columns but it could affect their ductility. When the centerline of columns coincided with the centerline of wing wall, the reinforcement was better.In the paper, the Mx-My envelope curves before reinforcement and after reinforcement in practical engineering were comparative analysis. The results showed additional wing wall reinforcement method could effectively improve the bearing capacity and rigidity of the column. In this paper, the effect of reinforced columns on beams and wholeness of the structure were not researched, these problems still need further research.