Study Of Seismic Performance Of Precast Segmental Bridge Piers

Precast segmental piers mainly adopt prestressed structure,its prestress level is higher than that of integral bridge piers,which will generate greater prestress loss,and prestress loss has important influence on the seismic performance.This paper studies the subitem “The effect of prestress on segmental bridge pier's seismic performance” from the project “Numerical analysis and experimental study on seismic performance of prestressed concrete segmental bridge pier." of the Science and Technology Project of Sichuan Provincial Transportation Department.Using the hollow rectangular precast segment pier as the research object and using the quasi-static experiment and numerical simulation of OpenSEES as the method.The quasi-static experiment of the three sets of segmental pier is designed and implemented.Through the conparison of experimental results and numerical simulation results,how the seismic performance is affected by prestress loss is mainly analyzed,main work is as follow:(1)Aiming at the problem of the effect of prestress on seismic performance of precast segmental bridge pier,the literature investigation has been done.Summarizing the existing domestic and foreign scholars' theoretical research and experimental study progress for the seismic performance of prefcast bridge pier structure,and introducing the engineering application state of the existing piers which precast structure is adopted.Analyzing the basic concept of precast bridge pier and the focus of quasi-static experiment,putting forward the research direction of this paper.(2)Structure design and numerical simulation.Based on the investigation and research,three sets of prestress precast concrete segmental bridge piers are designed and producted.The fiber finite element model is established to simulate the pier by using the OpenSEES.Using the ABAQUS(solid element)and Xtract(cross-section)model to proofread the OpenSEES(fiber element)model and verifying the validity of the numerical model established in OpenSEES.(3)Quasi-static experimentizing and data processing.Based on the numerical simulation,the experimental scheme was formulated.In the quasi-static experiment,the data such as displacement,bearing capacity,strain,curvature,and joint opening angle were collected at different prestress levels.After processing the data(hysteresis curve,stiffness,ductility,etc.),the mechanical properties of piers at different prestress levels under quasi-static loads are examined and the seismic performance of the piers after prestress loss and its failure mechanism is analyzed(4)Summarizing and contrasting the experiment and numerical simulation(yield limit and bearing capacity,the similarity of pinch effect,the residual displacement is not obvious,etc.).Focusing on the impact of prestress on the seismic performance of bridge piers.