Study On The Seismic Behavior And Design Method Of Composite High Pier With Concrete-filled Steel Tube （CFST） And Soft Steel Energy Dissipating （SSED） Components

In order to solve the problem of rapid repair of bridge piers after earthquake,this paper proposes a concrete filled steel tube-soft steel energy dissipation（CFST-SSED）components combined high pier,give full play to the mechanical properties of steel tube concrete structure and steel structure,it not only has excellent energy dissipation capacity,and a prefabricated and earthquake quick quick fixes,change a bit.In order to study the seismic behavior and failure mechanism of SSED and CFST-SSED composite high piers.This subject mainly carries out the following work:（1）This paper introduces the seismic performance of the existing concrete-filled steel tubular piers and steel piers and the research status of post-earthquake repair technology.The application methods of large finite element software ABAQUS in pre-processing,solver call and post-processing are introduced.（2）The diameter-thickness ratio,length-diameter ratio,length-thickness ratio and whether or not stiffener is used as the varying parameters of the energy dissipating parts of soft steel,and two sets of 24 finite element models are designed for calculation.The stress cloud map,equivalent plastic cloud map,hysteretic curve,skeleton curve,load bearing capacity,deformation capacity,stiffness degradation and energy dissipation capacity under different parameters were compared to analyze the law of the influence of each parameter on the seismic energy dissipation performance of the energy-dissipating parts of soft steel.Simulation shows that the SSED parts with outer soft steel inner core structure steel,have very good energy dissipation capacity and ductility performance.（3）Soft steel of the energy dissipation is determined based on the above parts design parameters,set up three CFST-SSED combined-type high pier model,the combined block model on soft steel energy dissipation components of energy dissipation performance further explore,through the comparison and analysis model of equivalent plastic stress nephogram,cloud,hysteresis curves,skeleton curves,deformation,stiffness degradation,energy dissipation capacity,discusses the seismic performance of composite bridge pier and outer steel stiffening rib on the energy consumption combined pier model the influence of various performance.The results show that CFST-SSED composite high pier gives full play to the advantages of the two structures and has good energy dissipation capacity.Based on the results of finite element analysis and other literatures,the structural design parameters of SSED and the design value formula of limit strength of the energy dissipating parts of soft steel are presented.