Study On Seismic Behavior Of CFST Column Corrugated Steel Plate Composite High Pier

As an important part of basic transportation construction,bridge is an important transportation hub connecting cities and towns,which plays a vital role in promoting the economic development of the country and region.In this paper,based on the seismic concept of single pier and multi column,the CFST column corrugated steel plate composite high pier is proposed.CFST column is used to replace reinforced concrete column and corrugated steel plate is used to replace reinforced concrete slab.Quasi static simulation and nonlinear time history analysis are carried out for CFST column corrugated steel plate composite structure and CSFT column corrugated steel plate composite high pier respectively1)Based on the material constitutive model in this paper,the finite element models of CFST column and corrugated steel plate frame shear wall with existing test data are established,and the simulation results are compared with the test results.The results show that the material constitutive model used in this paper can well simulate the failure position and mechanical performance of CFST column and corrugated steel plate frame shear wall,The accuracy of the simulation is verified.2)Four groups of CFST column corrugated steel plate composite structures are established,and the wave direction and thickness of corrugated plate are analyzed.It is found that with the increase of plate thickness,the bearing capacity,ductility and initial stiffness of the structure increase,but it is not conducive to the stiffness degradation of the structure.The ductility of the transverse plate is 2.1 times of that of the vertical plate,and the stiffness degradation of the transverse plate is slow.3)The failure mechanism of CFST column corrugated steel plate composite structure is studied.The results show that the yield order of steel pipe,beam and corrugated plate is corrugated plate column base middle beam upper beam;The column base of the transverse corrugated plate structure will bend inward during the displacement loading,which leads to the fact that the upper corrugated plate of the transverse corrugated plate structure still has more elastic reserves at the end of the displacement loading;When the thickness of corrugated plate increases,the middle beam will bend inward when the displacement is large;For the middle beam,the stress at the web develops earlier than that at the flange;The concrete at the bottom of CFST column is crushed at first,and finally the concrete at the top of CFST column is also damaged,but the concrete of shear wave structure is also damaged at the position of middle beam.4)The parameters of CFST column corrugated steel plate composite structure are analyzed by four groups of parameters: wave height,wave distance,concrete strength and hoop coefficient.The results show that wave height,wave distance and hoop coefficient have great influence on the mechanical properties of the structure,while concrete strength has little influence.5)The CFST column corrugated steel plate composite high pier is established,and the natural vibration characteristics and nonlinear time history analysis of the high pier are carried out.At the same time,the influence of different hoop coefficients on the seismic response of the whole bridge model is compared.The results show that when the first-order natural vibration period of the high pier is 1.50 s,and the hoop coefficient is 0.67,the transverse and longitudinal displacement of the pier top are 18.3mm and 11.4mm respectively;Under rare earthquake,the displacements of pier top in transverse direction and under bridge are154.7mm and 87.0mm respectively.