Seismic Behavior Of New-type Box Steel Pier Column With Embedded Energy-dissipating Shell Plates

In this paper,a new type of urban viaduct box-shaped steel pier is designed based on the principle of damage control.Arc low-yield-point steel plates are set as energy-consuming components at the root corners of the box-shaped steel pier column.This new type of steel pier column is efficient for on-site construction and post-earthquake detection and repair.In addition,embedded energy-consuming shell plate can effectively decrease the extent of stress concentration at the corner of the box-shaped steel bridge pier and then can prevent tearing of the vertical welds at the corners.According to the mechanics characteristics of the real steel bridge pier,the axial compression steel pier was selected as the research object.The seismic performance of box-shaped steel pier was studied by using the experimental and finite element simulation methods.The study provides a large amount of experimental data for the seismic design of the steel piers,and provides the theoretical basis for the engineering application of the steel piers.The space interval of the transverse stiffener,the strength of the embedded shell and the axial pressure ratio are selected as changing parameters.10 box-shaped steel studs were designed for quasi-static tests.The loading scheme,the loading device,and the measurement contents are described in detail.The local buckling of the web and the flange of the specimen and the failure of the specimen were observed.The horizontal displacement and load at the top of the specimen and the strain state distribution of the web and flange are measured by the data acquisition system.The local buckling and failure phenomena of 10 specimens were analyzed and the conclusion was drawn.The load-displacement hysteresis curve,skeleton curve and load-strain curve of the specimen are obtained,and the displacement ductility coefficient and bearing capacity of the specimen are obtained.The effects of transverse stiffening pitch,inner shell strength and axial compression ratio on the seismic performance of box-shaped steel pier are analyzed synthetically.The results show that the deformation capacity of the box-shaped steel pillar column is enhanced and the ductility is better after the inner shell is set.The smaller the lateral stiffening spacing and the axial compression ratio,the greater the displacement of the specimen and the ultimate bearing capacity.The more gentle the skeleton curve is,the better the deformation capacity and ductility of the box steel pier.In the case of a stiffened stiffener,the effect of changing the strength of the inner shell on the skeleton curve of the box steel pier is very small,which has no significant effect on the deformation ability and ductility.In the case of the inner shell shell yield strength f = 100 MPa,whether or not to set the wall stiffener has little effect on the skeleton curve.In the end,the finite element simulation of box-shaped steel pier is carried out.The stress characteristics of box-shaped steel stud columns under constant axial force and reciprocating horizontal load are analyzed.The load-displacement curve,the skeleton curve and the test curve are simulated and analyzed.Based on the aforementioned finite element model,23 components,whose range of parameter variation is expanded,are designed.The influence of the parameters such as transverse stiffening interval,inner shell thickness,inner shell shell curvature,axial compression ratio and slenderness ratio on the seismic performance of box-shaped steel pier column is analyzed.