Experimental Study On Failure Modes Of Reinforcedconcrete Box Columns Under Pseudo-static Load

In order to study the reinforced concrete box columns under the action of earthquake damage form and its influencing factors,this paper deals with six scale component pseudo-static test and related theoretical analysis,through comparing the result of the test data and theoretical analysis,studied the flange and web width height ratio,reinforcement ratio and section height to width ratio of reinforced concrete box column failure pattern;Secondly,based on the experimental data,the restoring force model of the control parameters of the box wall thickness ratio is established,and the calculation procedure of the model is written.Finally using nonlinear analysis software ABAQUS to simulate experiment content,to verify the validity and feasibility of the mentioned analysis model to explore the applicability of the restoring force model,and verified the calculation formula of ultimate bearing capacity.The results are as follows:(1)improvement of the reinforcement ratio of the box wall can effectively improve the bearing capacity and energy dissipation capacity of the components,but the ductility performance and deformation ability will be reduced in a certain extent.(2)decreasing the high width ratio of the section decreases the ductility performance and energy dissipation capacity of the components,while the bearing capacity decreases with a small amplitude and the stiffness degradation accelerates.It can greatly increase the ductility,energy dissipation capacity and horizontal ultimate bearing capacity of the components and reduce the stiffness degradation.It can increase the ductility and energy dissipation capacity of the member with a certain amplitude,but it has little effect on the degradation of the horizontal ultimate bearing capacity and stiffness.(3)the calculation formula of horizontal ultimate bearing capacity of reinforced concrete box columns is presented based on experimental data and theoretical analysis.(4)the establishment of the restoring force model can be more convenient structure and characteristic values such as structures related to the damage form of the yield point,the bearing capacity limit point and stiffness reduction factor,etc.,thereby for the design of the control parameters is wall thickness change to the same type quick analysis failure provides a better means of auxiliary.In this paper,through test and research,combined with the theoretical analysis and finite element simulation,get the damage form of reinforced concrete box column and its influencing factors,the effects of these factors are analyzed,for further research and hascertain reference value for engineering applications.