Seismic Behavior Study On The Embedded Steel-concrete Connections In Gasification Frame

As a key components of gasification frame structure connecting steel superstructures and concrete substructures,the embedded column transfer joint plays a crucial role on the mechanical behavior of gasification frame structures.Because the force and deformation of the embedded column transfer joints under seismic load play an important role during earthquake,it is necessary to investigate the mechanical behavior of the embedded column transfer joint under low cyclic loading.This paper takes the embedded column transfer joint used in a gasification frame structure designed by the China Huanqiu Contracting & Engineering corporation as object,low-cycle reversed loading experiment and simulation methods were carried out to study the seismic performance of the embedded column transfer joint.(1)With a similar ratio of 1 to 4,4 model specimens of the embedded column transfer joint are designed and manufactured.This paper mainly study the effects of arrangement of studs,the extension depth of section steel and concrete cover thickness of section steel on the seismic performance of the embedded column transfer joint,including failure patterns,hysteretic loops,skeleton curves,ductility,energy dissipation capacity,strength and stiffness degradation.The results showed that seismic performance of the embedded column transfer joint is good.The ductility factors of the 4 specimen joints are from 3.99 to 4.64,which meet the requirements for seismic design,and their equivalent viscous damping coefficients at the maximum loads are from 0.186 to 0.295,indicated that the energy dissipation is higher.The arrangement of studs has little effect on seismic performance of embedded column transfer joint.The seismic performance of the specimen is enhanced by the increase of the extension depth of the steel and concrete cover thickness of section steel within a certain range.(2)The finite element models of the model specimens were established by ABAQUS.Nonlinear analysis was performed on the embedded column transfer joint.To verify the finite element model,numerical analysis results were compared with the text results.(3)The finite element models of the full-scale models were established by ABAQUS.Parametric analysis was performed on the embedded column transfer joint.The effects of axial compression ratio,the extension depth of section steel and concrete cover thickness of section steel on seismic performance of the embedded column transfer joint.The results showed that the ductility of the embedded column transfer joint decreases with the increase of axial compression ratio.When the depth of the section steel is 0.4 ~ 0.6 times of column height,the ductility factors are from 3.73 to 3.76.The bigger the concrete cover thickness of section steel,the better the ductility of the transfer joint.