Experimental Study On Plastic Hinge Length Of Reinforced Concrete Box Column Under Quasi-static Load

In order to explore the influencing factors and laws of plastic hinge length of reinforced concrete box column under the action of earthquake,six scale members were made by combining with the actual bridge piers in the project,and analyzed by combining the pseudostatic test and relevant theories.Based on the data of quasi-static test,the influencing factors of plastic hinge length(transverse to longitudinal wall thickness ratio,sectional longitudinal reinforcement ratio and sectional aspect ratio)and the influencing rules of reinforced concrete box columns are analyzed.Then finite element analysis software ABAQUS is used to simulate the quasi-static test,which verifies the correctness of the test results.At the same time,more models are established to further study the influence of the three factors of transverse and longitudinal wall thickness ratio,sectional longitudinal reinforcement ratio and sectional aspect ratio on the development law of plastic hinge length.The research results are as follows:1.reducing the length-width ratio of the specimen section has a significant effect on the growth of the plastic hinge length of the specimen during the period from reinforcement yield to peak load;With the gradual increase of load,the improvement of plastic hinge length is relatively small in the period from load peak to ultimate displacement,and it is found that the change of section size along the loading direction has a more significant impact on the plastic hinge length.2.the change of wall thickness ratio of specimen at the peak load stage in front of the plastic hinge length,however,as the load increases gradually,when the components in the ultimate displacement state,found that the increase of the longitudinal wall thickness than to improve the development of the plastic hinge length has a very good role in promoting,and lateral wall thickness ratio on the plastic hinge length is not significant.3.the improvement of the longitudinal reinforcement ratio has a significant effect on the improvement of the plastic hinge length during the period from the yield state to the peak load state of the box column,and the lifting effect is negatively correlated with the initial longitudinal reinforcement ratio of the member;The reinforcement ratio of longitudinal reinforcement can improve the plastic hinge length during the period from peak load to ultimate displacement of box column,and the lifting effect is positively correlated with the initial reinforcement ratio of longitudinal reinforcement.In this paper,through the study of quasi-static test,combined with relevant theoretical analysis and finite element simulation,the influencing factors and influencing rules of plastic hinge length of reinforced concrete box column are obtained,and the research results will provide relevant references for the subsequent research and engineering application.