Study On Seismic Behavior Of A New Type Of Precast Insulation Shear Wall With Diagonal Bracing

Precast reinforced concrete shear wall structure has a good prospect because of its advantages of good integrity,high bearing capacity,large lateral stiffness,short construction period,high engineering quality and environmental protection.However,due to the large seismic action,the relatively poor ductility and the difficulty in the installation of wall panels,its engineering application is limited.Therefore,it is of great significance to optimize the design of shear wall structure to design a precast reinforced concrete shear wall structure with good ductility,high energy dissipation and simple construction.Based on the concept of prefabricated structure,combined with the advantages of shear wall with diagonal bracing and hollow shear wall,this paper presents a new type of precast shear wall——precast insulation shear wall with diagonal bracing.A series of research work has been done in this paper for studying the seismic behavior of this shear wall.The main research contents and conclusions are as follows:(1)Low cyclic reversed loading experiments had been conducted on three diagonal bracing insulation shear walls with three different shear span ratios of 1.0,1.5,2.0 respectively.Systematic analyses were made on failure modes,hysteretic curves,skeleton curves,bearing capacity,deformation capacity,stiffness degradation,energy dissipation capacity,lateral displacements and strain of steel bars of the different specimens.The same experiment on an ordinary shear wall with shear span ratio of 1.5 was carried out to make a comparative analysis of the seismic behavior.The results show that for the same shear span ratio,the bearing capacity of the insulation shear walls with diagonal bracing is slightly lower than that of the ordinary shear wall,however,the development of the cracks are delayed,the ductility and energy dissipation property of the wall increases significantly.As the first line of defense against earthquake in the web,the diagonal bracings yield first and give full play to their resistances and energy dissipation capacity under reversed loading.As for insulation walls with diagonal bracing,with the shear span ratio increasing,the bearing capacity decreases,whereas deformation ability increases,stiffness degradation delays and energy dissipation capacity increases.(2)In order to verify the reliability of finite element analysis software ABAQUS,the numerical simulations were carried out on the experimental specimens.Systematic analyses were made on failure modes,stress of steel bars and skeleton curves of the different specimens.The results show that ABAQUS can well simulate the seismic behavior of the specimens with the comparisons of experiment results.(3)In order to optimize the design of precast insulation shear wall with diagonal bracing,parametric analysis were carried out by the finite element analysis software ABAQUS.Choosing axial compression ratio,reinforcement ratio of diagonal steel bars,reinforcement ratio of beam longitudinal bars and hollow thickness as parameters.Studying the influence on seismic behavior of diagonal bracing insulation shear walls when these parameters changed.The results show that when design axial compression ratio is 0.25~0.34,reinforcement ratio of diagonal steel bars is 0.84%~1.31%,reinforcement ratio of beam longitudinal bars is 0.44%~0.67% and hollow thickness is 50 mm,the seismic behavior of the insulation wall with diagonal bracing is optimal.