Research On Seismic Performance And Vibration Control Of Hybrid Reinforced Self-Resetting Bridge Structures

In recent years,bridges have gradually become an important part of infrastructure construction,and their construction efficiency and environmental protection have received widespread attention.For the traditional cast-in-place reinforced concrete piers,there are disadvantages of damage to the surrounding environment and long construction period during the cast-in-place construction process,and excessive damage and residual displacement will occur after the earthquake,which is not conducive to the repair of piers after the earthquake.As a new structural form that has emerged in recent years,self-replacing segmental assembled bridge piers can be divided into several segments and connected into a whole structure by prestressing tendons or other connection methods,which makes it have the advantages of less damage to the surrounding environment during construction and shorter construction period.However,the segmental assembled piers are composed of several segments,which improve their self-resetting ability,but their energy dissipation capacity is insufficient and largely reduce the seismic performance of the bridge,thus affecting the use of segmental assembled bridges in high-intensity areas.To address the above-mentioned defects of segmental assembled bridges,this paper proposes a hybrid reinforcement idea for self-replacing segmental assembled bridges,i.e.,to add energy dissipating reinforcement and self-replacing reinforcement as longitudinal tensile reinforcement in addition to prestressing reinforcement in the pier body to improve its energy dissipation capacity and seismic performance.Among them,the energy dissipating reinforcement adopts HRB400 reinforcement and the self-resetting reinforcement adopts Fiber Reinforced Polymer(FRP)reinforcement.HRB400 reinforcement and FRP reinforcement play the role of increasing the energy dissipation capacity of the bridge pier and reducing the residual displacement of the pier after the earthquake respectively.This paper mainly accomplishes the following research:1.Two finite element modeling methods for self-resetting piers are analyzed,namely Kurama model method and zero-length element simulation joint method.2.In order to study the change of stiffness of the composite reinforcement self-resetting segmental pier under external load,the analytical expression of the equivalent elastic stiffness of the composite reinforcement self-resetting segmental pier is derived by using the finite strip method.The finite element model of composite reinforcement self-resetting segmental assembled pier is established by using Opensees,and the reliability of the analytical expression of equivalent elastic stiffness is verified.3.In order to enhance the seismic performance of prefabricated assembled bridges,a new viscoelastic bearing is proposed in this paper,which can effectively improve the vibration control of self-resetting segmental assembled bridges by using the relative shear and torsional coupling between viscoelastic materials to achieve the vibration isolation effect.The finite element model of the prefabricated bridge with the new viscoelastic bearing is established by using the finite element software Opensees,and the non-linear time-response analysis is compared with that of the unsupported segmental assembled bridge to verify the vibration reduction and isolation effect of the proposed bearing.