The Study Of Seismic Response Of Precast Segmental Box Girders With All External Tendons

The application of bridge approaches of the second Wuhu Yangtze river bridge is the first fully externally prestressed and segmentally precast assembled girders,the grand scale of the project,industrialization,standardization,assembly,to ensure quality and improve durability,easy to detect and replace with external tendons.The structure of the design is novel,compared with the traditional continuous beam has a significant innovation,improve the efficiency of the use of external prestressed,greatly reducing the amount of concrete,reducing the bridge structure weight,direct economic benefits significantly.However,there is no complete seismic design theory and seismic design method on the relevant design specifications of domestic bridges for the type of bridge with the relevant seismic resistance and the seismic damage,which brings great difficulties to the seismic design and seismic construction measures,will seriously hinder the type of bridge to promote the application.This paper deals with finite element model,dynamic characteristics and seismic response of bridge approaches of the second Wuhu Yangtze river bridge.The main research results are as follows:(1)Grasping the domestic and foreign research situation related to externally prestressed girders and segmentally precast assembled girders,the research results of dynamic characteristics and seismic design are reviewed comprehensively.(2)The dynamic characteristics of the real bridge are carried out,based on the project of the approach of the second Wuhu Yangtze river bridge.(3)The multi-scale and refined finite element model is established for fully externally prestressed and segmentally precast assembled girders.(4)Through the comparison and analysis of the actual dynamic test data of the real bridge and the calculation results of the space bar and refined finite element models,the correctness of the refined finite element model is verified,and the important design parameters are studied for the influence of dynamic characteristics of fully externally prestressed and segmentally precast assembled girders.(5)The seismic responses are studied of fully externally prestressed and segmentally precast assembled girders,especially the special damage caused by special structure of superstructure.