Experimental Study On Seismic Behavior Of Concrete Box Columns Based On The Change Of Steel Reinforcement Ratio

In order to study the effect of reinforcement ratio on seismic performance of reinforced concrete box-section columns,two scaled members are designed according to the ratio of 1:10,and the quasi-static test and related theoretical analysis are carried out.Through the comparison of experimental data analysis and theoretical analysis,the influence of reinforcement ratio on ductility,bearing capacity and energy dissipation capacity of reinforced concrete box-section columns is studied.Secondly,through the analysis of experimental data,a restoring force model with reinforcement ratio as design control parameter is established.Finally,the conclusion of theoretical analysis is verified by finite element analysis software ABAQUS.The applicability of the formula for calculating the horizontal ultimate bearing capacity is verified.The results are as follows:(1)In the range of 1.58%~2.21% reinforcement ratio,with the increase of reinforcement ratio,the energy dissipation capacity and horizontal ultimate bearing capacity of the specimens increase obviously,The ductility of the specimens also increases,but it will decreases when the reinforcement ratio of the specimens approaches 2.21%;(2)Within this range of reinforcement ratio,increasing reinforcement ratio is beneficial to slow down the stiffness degradation of specimens after yielding,but when the maximum bearing capacity of specimens reaches the failure stage,it will accelerate the reduction of the bearing capacity of specimens;(3)The validity of the formulas for calculating the normal section strength and the ultimate horizontal bearing capacity of box section proposed by Shi Wenxian and Qiaogang is verified by analyzing the test data and combining with the finite element analysis;(4)The restoring force model with reinforcement ratio as design control parameter is beneficial to provide a better assistant means for rapid determination of reasonable reinforcement ratio for similar members.In this paper,through quasi-static test,combined with relevant theory and finite element simulation,the influence of reinforcement ratio on energy dissipation capacity,ductility,bearing capacity and stiffness degradation of reinforced concrete box-section columns is obtained,and the reasonable range of reinforcement ratio is analyzed,which has certain reference value for subsequent theoretical research and engineering practice.