Research On The Performance-based Seismic Design Of Concrete Filled Square And Rectangular Steel Tubular Pier

In the early stage of seismic fortification,single fortification level is set as standard to ensure the safety of structures.But strong earthquakes which caused serious damage in the late 20 th century let people realize the limitations of single fortification level,and with the increasing recognition of aseismic design,performance-based seismic design theory gradually formed and developed by researchers.However,there is no formal report of performance-based seismic design theory aiming at concrete filled square or rectangular steel tubular pier.Meanwhile concrete filled square or rectangular steel tubular pier is used more and more widely in engineering because of its excellent performance in many aspects.This paper uses the method combining theory with experiment and simulation to study it.The main content and conclusions of the research are as follows:1.According to the characteristics of rectangular concrete filled steel tube,related reference standards and literatures all over the world,the seismic fortification levels and performance levels of rectangular concrete filled steel tube pier are determined;the reason why the same performance levels are adopted for both square and rectangular tubes is discussed,and the performance goal matrix of different grades bridge piers is determined combined with bridge seismic fortification category.2.Several common design methods based on performance are overviewed,and seismic design method based on displacement of the rectangular concrete filled steel tube is discussed and determined.How to select suitable seismic displacement response spectrum is elaborated,and the max horizontal earthquake influence coefficient is adjusted combined with the latest architectural structure specification.The calculation methods of equivalent damping ratio and bending bearing capacity of concrete filled square and rectangular steel tubular pier are determined by referring to relevant technical regulations and literatures.3.Bending tests of rectangular concrete-filled steel tube column have been carried out,and the finite element analysis software ABAQUS is used to simulate the bending test.The result shows that the finite element simulation coincide with test and the referenced formula of flexural bearing capacity is accurate.Finally demonstration calculation is performed using the seismic design method based on displacement mentioned in the third chapter.Capacity spectrum method is used to verify the calculation result,the verification result shows that the seismic design method based on displacement is feasible.