The Analysis Of Safety On The Prefabricated Bridge Piers Based On The Emulative Design Principle

In recent years,the prefabricated assembly technology has been widely applied due to the less-polution and convenient construction.Many scholars have conducted research on it,which was greatly improved the level of construction technology.With the popularization and application of the prefabricated piers,the structure detail in the plastic hinge area of the prefabricated piers connection structure and seismic safety performance are getting more and more attention.The research work is as follows:Firstly,a simple-supported subway bridge pier on construction was taken as background,two kinds of prefabricated piers,mechanical sleeve and screw thread steel bar were designed and quasi-static tests were performed.Based on the damage and performance of the specimens,the damage mode and the crack pattern of each specimen were analyzed,and each stage of destruction of each specimen were recorded.Secondly,based on the test results,the skeleton curves,hysteresis curves,initial stiffness,equivalent stiffness,unloading stiffness,energy dissipation capacity and viscous damp of each pier were analyzed.It is found that the prefabricated piers with mechanical sleeve connections and the whole cast-in-situ piers have nearly equal mechanical properties,while the prestressed piers have less energy dissipation capacity than the whole cast-in-place piers.After that,the cross-section analysis method was used to calculate the load and displacement corresponding to the yield point,the maximum load point and the complete failure point according to the bending moment-curvature.The formula of restoring force mode for each specimen was derived according to the theoretical calculation and the empirical formula,The theoretical skeleton curve of each specimen was compared with the experimental skeleton curve,and it is found that the established model of restoring force of skeleton curve has satisfactory aggrement.Also,the hysteretic rules of prefabricated pier can provide a reference for the seismic theoretical analysis of metro viaduct pier.Finally,by discussing the plastic damage model used in concrete,the ideal elasto-plastic model used in steel bar and the contact model of joints in ABAQUS,the numerical calculation of the whole process of the prestressed segment piers with ABAQUS is suitable,and the comparation on the seismic performance between the axial load ratio and initial prestessing stress were addressed.