Seismic Behavior Of Restorable High-Strength Steel Circular Tubular Pier With Embedded Energy-Dissipating Shell Plates

Frequent earthquakes bring great risks to the construction and development of modern cities.As a key part of modern infrastructure transportation facilities,seismic damage of bridge will hinder the rapid recovery of post-earthquake city.The seismic behavior of the pier as a supporting structure of the bridge is closely related to the seismic behavior of the bridge.Based on the theory of damage control,this paper proposes a kind of high-strength steel circular tubular pier with embedded energy-dissipating shell plates,which can be recovered after earthquake.It is devoted to improving the seismic performance and restorable function of the pier so as to reduce the earthquake damage of the bridge.Considering the local buckling damage of the panel at the root of the pier is easy to occur under the earthquake,the replaceable energy-dissipating pier is set on the bottom of the high-strength circular tubular pier,and embedded energy-dissipating shell plates is set in the inside of the panel of the pier for reinforcement.The pier under the action of earthquake with dissipation of seismic energy concentrated cumulative plastic damage,and the rapid replacement of pier in the original site can restore the normal function of the pier after the pier is subjected to the earthquake.To understand the seismic performance of this kind of new cicular tubular steel bridge,high-strength steel cicular tubular pier is used as the research object.The pseudo-static experimental study on the seismic performance of the pier under axial compression and bias compression on the top of the pier are respectively conducted.The impact of setting embedded energy-dissipating shell plates and the change of axial compression ratio on the seismic behavior of high-strength steel cicular tubular pier is discussed through these performance index that load-displacement hysteresis curve,the load strain hysteresis curves,skeleton curves,displacement ductility coefficient,load capacity,stiffness degradation,strength degradation and energy dissipation capacity which are obtained from test results,and the mechanical characteristics and failure mechanism of the kind of high-strength steel cicular tubular pier is analyzed so as to provide the suggestions and theoretical basis for seismic design of this kind of pier in practical engineering.The results show that the load bearing capacity of high-strength steel cicular tubular pier is less affected and the failure pattern is more affected by the energy-dissipating shell plates.After the embedded energy-dissipating shell plates is set,the ductility,deformation capacity and energy dissipation capacity of high-strength steel cicular tubular pier are increased,especially the deformation capacity and energy dissipation capacity are greatly increased.Setting the embedded energy-dissipating shell plate can reduce the residual deformation of the top of high-strength steel cicular tubular pier and facilitate the post-earthquake repair of the pier.Under the action of axial pressure and horizontal reciprocating load,the energy dissipation capacity of high-strength steel cicular tubular pier with embedded energy-dissipating shell plate is greatly affected by the axial pressure ratio.With the increase of the axial pressure ratio,the energy dissipation capacity of high-strength steel cicular tubular pier with the embedded energy-dissipating shell plate is gradually increased.Under the action of eccentric pressure and horizontal reciprocating load,the axial compression ratio has little influence on the bearing capacity of high-strength steel cicular tubular pier with embedded energy-dissipating shell plate,and the axial compression ratio has great influence on their ductility,deformation capacity,energy-dissipating capacity and failure form.