Study On Axial Compression Performance Of High-strength Steel Circular Tube Bridge Pier With Energy Dissipating Shell Plates

As the key bearing structure of bridge,the damage of bridge pier plays an important role in the overall damage of bridge structure.Steel bridge piers have excellent characteristics such as light weight,good ductility,high strength,less construction area,short construction period,and post-earthquake repairable.Steel structure is the material of green and sustainable development,and more and more steel structures are applied to bridge construction.With the further development of steel research,high strength steels and low yield point steels have been developed.The mechanical properties and composition indexes of new steels are different from the ordinary strength structural steels,and the performance of new steel in practical engineering application needs to be further explored.To this end,this subject proposes a high-strength steel circular tube bridge pier with energy dissipating shell plates,and an arc-shaped low yield point steel plate is embedded at the root of the pier to give full play to the bearing capacity and ductility of the component.Designed four sets of 8 Q460 high-strength steel circular tube bridge pier for axial compression test research.Four key parameters are proposed as control variables: whether to setting up longitudinal stiffeners,the strength of low yield shell panels,the connection mode of energy dissipating shell plates,and low-yield-point steel plate thickness.The mechanical characteristics such as the failure mechanism,bearing capacity,and ductility of the test piece under axial compression were discussed.The performance of the mechanical performance and the test process of the highstrength steel bridge pier with energy dissipating shell plates and the standard test piece and the ordinary stiffener were compared and analyzed.During the test,there are mainly three types of specimen failure:(I)local buckling deformation mainly occurs in the "foot-like" failure of the root of the specimen,mainly plastic deformation;(II)local buckling deformation of the root wall of the specimen After that,the high-strength bolts were cut off;(III)The "flattened" large deformation and damage occurred on the upper and lower parts of the test piece,and the material damage mainly occurred,giving full play to the material strength.Comparative analysis test results show that,energy dissipating shell plates can significantly improve the bearing capacity and ductility under the axial load.Obvious signs of deformation before damage,mainly ductile damage.There is no obvious yield step in the loading process of the specimen,and the deformation is mainly concentrated after the occurrence of the maximum bearing capacity,and the strength reserve value of the component is large.The ultimate bearing capacity of the test pieces with longitudinal stiffeners reinforced by ordinary reinforcement is lower than that of standard test pieces.The main reason is that the longitudinal stiffeners are not installed in length and thus do not play a role in the test.The impact of the test piece on the bearing capacity of the test piece,especially the structure of the built-in energy dissipating shell plates,has a more significant effect on the improvement of the load bearing capacity.The strength and thickness of the low yield plate have a certain effect on the bearing capacity of the test piece.As the strength of the low yield plate increases,the ultimate bearing capacity of the test piece increases.At the same time,as the thickness of the low yield plate increases,the ultimate bearing capacity of the test piece increases.,And the thickness has a greater impact on the test load capacity.