Numerical Analysis Of Seismic Performance Of Precast Segmental Assembly Bridge Piers

Precast segmental bridge piers can show good self reset ability in earthquake action.The setting of prestressed reinforcement and the connection mode between segments affect the seismic performance.The purpose of this study is to study the effect of different structures on the seismic performance of precast segmental piers.The test and application of prefabricated pier at home and abroad are analyzed.The prefabricated segmental bridge pier model was established.The performance is compared between the bond and unbond of the prestressed reinforcement.The influence of position layout of prestressed reinforcement and energy dissipating bar on seismic performance is studied.The local cast-in-place structure has been proposed.The seismic performance is verified.The research work and conclusion of this paper mainly include the following aspects:(1)In precast segmental assembly bridge piers,The prestressed reinforcement and the pier column are in a state of bond.Compared with the unbonded treatment,the lateral force ability of the pier column increases obviously,and the stiffness of the pier column is obviously improved.It can be applied to low intensity areas.The unbonded prestressed reinforcement should be adopted in the high intensity area,so that the pier column has a good self reset ability.(2)Energy dissipating bar is arranged between the prefabricated pier.Energy dissipating bar can greatly improve the energy dissipation capacity of the pier column.Performance is compared with several different placement positions of prestressed and energy dissipating steel bars.The moment of inertia of the section of steel bar is introduced to quantitative analysis.The results show that when the moment of inertia is the same in the cross section of the prestressed reinforcement,the greater the moment of inertia in the section of the energy dissipating bar,the better the seismic performance of the pier column.When the moment of inertia is the same in the cross section of the energy dissipating bar,the greater the moment of inertia in the section of the prestressed reinforcement,the better the seismic performance of the pier column.(3)Local cast-in-place treatment is used to connect the joint of the Precast Pier segment to the segment.The bond relationship between the local cast-in-place concrete and the precast concrete is studied.The feasibility of local cast-in-place is verified.Through the comparison of segmental bridge column without cast-in-place concrete and local interface,It is shown that the use of local cast-in-place structures can enhance the connections between segments.Precast segmental columns has good integrity.The energy dissipation capacity and lateral force resistance of the pier column are improved.Moreover,the local cast-in-place structure is also easy to repair after the earthquake,and only need to be cast after the contact surface treatment.