Numerical Analysis Of The Factors Affecting The Ductility Seismic Performance Of Cylindrical Piers

Reinforced concrete piers are important load-bearing elements of the bridge structure.They are often subject to various degrees of damage which affects the stability of the bridge directly under strong earthquake loads. It caused great threat to human life and property. Ductility of pier is directly related to their seismic performance, so it is the main idea that needs to be considered how to design to improve the ductility of the seismic performance in bridge seismic design specifications nowadays. It is mostly used in reinforced concrete structures for today’s pier, so the study of factors and how these factors affect reinforced concrete ductility become especially important.In this paper, we use non-linear finite element software ABAQUS to analyze the factors affecting the ductility of cylinder piers based on reciprocating load Pushover analysis, the main research work are the following several aspects:(1) Describing typical damage cases, failure mode of the piers in the history and the development overview of experimental research on seismic performance of pier. Summarize the main contents about the design and analysis of seismic performance. Generalizing the main method about analysis of ductility seismic performance and simulating yielding process of cylindrical protective layer of concrete pier, stirrups and longitudinal reinforcement under various conditions.The yield of core area’s concrete can be kNown by judging the appearance of ultimate displacement on skeleton curves.(2)Using non-linear finite element analysis software ABAQUS to simulate cylindrical piers, it can be kNown that axial compression ratio is increased to shorten the compression zone concrete first time by analyzing the yield change after changing compression ratio ductility. Displacement ductility factor also decreased, while the lower limit axial compression test of the ultimate destruction of parts corresponding larger displacement. And when the axial compression ratio increases, the cylindrical pier hysteretic energy capacity decreases, so small axial compression ratio can increase the ductility of the piers in a certain degree, and then raise the pier collapse resistance.(3)By analyzing ductility change of the different cylindrical pier stirrups and stirrup ratio we can kNow: compared with the circular hoop, pier’s ductility of spiral hoop has been improved, having more energy dissipation capacity. The secure area and non-encrypted area’s stirrup rate change of cylindrical pier’s stirrups pier have an impact on ductility, but the cylindrical pier’s stirrup rate change of secure area has much more effect on ductility and energy dissipation capacity than non-encrypted area stirrup ratio in the entire loading process.(4)By analyzing ductility change of the different cylindrical pier longitudinal reinforcement ratio and longitudinal reinforcements form we can k Now that the increase of longitudinal reinforcement rate enhances the carrying capacity of cylindrical piers, and the higher the stirrup ratio is, this change becomes more obvious; when the longitudinal reinforcement ratio is lower, the impact on cylindrical pier ductility and energy dissipation capacity is not obvious. Only when a higher rate of longitudinal reinforcement can improve the ductility of cylindrical pier and energy dissipation capacity significantly; when the stirrup ratio is lower, the increases of longitudinal reinforcement rate doesn’t have obvious effect on ductility of the cylindrical pier. Only when the stirrup ratio is larger, the increase of longitudinal reinforcement rate can change the ductility of cylindrical pier significantly, the higher the rate of longitudinal reinforcement is, the more obviously ductility increase. The longitudinal reinforcement arrangement does not affect displacement ductility and energy dissipation capacity obviously.(5)By numerically simulating Yang Li’s cylinder experiment, comparing FEM and experimental data, then validate the method of numerical simulation and the correctness of the conclusions chapter 3,4,5.Finally, this article summarized the achievements and shortcomings and made further research on the analysis of the cylindrical pier ductility.