Study On Seismic Behavior Of Post-tensioned Prestressed Bridge Piers

The prefabrication of bridge structure is an important development direction of bridge design in the future.A large number of on-site construction steps are completed in advance in prefabricated factories,which can improve the efficiency of construction work,avoid a large amount of construction waste pollution,effectively improve the traffic congestion around the construction,and a large number.Reduce vehicle exhaust emissions,greatly protect the safety of construction workers,and reduce engineering maintenance costs.In the high-intensity seismic region,the existing research has not fully understood the seismic performance of the prefabricated pier columns,which greatly hindered the application of the prefabricated piers in practical engineering.Taking the post-tensioned prestressed bridge pier as the research object,the quasi-static characteristics and dynamic response of the pier are studied.Based on the finite element software ABAQUS and the fiber beam element model method,the secondary development and application of concrete and steel hysteretic constitutive models are carried out to better analyze the seismic nonlinearity of segmental prestressed piers.The validity of the fiber beam element model is verified by comparison with two sets of quasi-static experiments made by Ou YC,and two typical test pieces are parametrically analyzed to reveal the segment assembly under different initial parameters.T he difference between the seismic performance of the piers and the main influence parameters of the ductility performance of the assembled piers are mainly studied in the following aspects:(1)Based on the existing literature,select a reliable constituti ve model of single-cycle hysteretic behavior of reinforced concrete materials,and numerically simulate the prestressed reinforced concrete bridge piers with existing tests,through load-displacement curves and quasi-static The comparative analysis of force experiments demonstrates the feasibility of the constitutive model of reinforced concrete materials,as well as the high calculation accuracy and efficiency.(2)Using the reinforced concrete constitutive model selected in this paper to numerically simulate the prestressed reinforced concrete bridge pier,avoiding the complexity of steel bar modeling,and reasonably revealing the assembled pier structure under low cycle reciprocating load The anti-seismic performance parameters such as hysteresis performance,energy dissipation capacity,and skeleton curve are proposed,and a reasonable seismic design scheme for post-tensioned prestressed bridge piers is proposed.(3)Based on the seismic fortification requirements of existing standard bridges,three sets of artificial seismic waves based on the design response spectrum are fitted,and the difference between segmental prestressed piers under different axial compression ratios is illustrated by dynamic time history analysis.Based on the research results of seismic performance of joints of bridges and suitable parameters of structural earthquake resistance,seismic design countermeasures for bridges with different axial compression ratios are formed,and segments with large axial compression ratio are displayed.The pier has better seismic performance.