Research On Static And Dynamic Performance Of Composite Girder Suspension Bridge And Design Method Of Light Weight Deck

Long-span bridges are widely used in domestic newly built highways in recent years.As a weak part of the bridge structure,bridge deck is prone to damaged.So the maintenance costs of the bridge increase year by year,and it also affects the rapid and stable growth of the national economy.This thesis summarizes the research status of bridge decks and illustrates the advantages and disadvantages of steel and concrete girder in suspension bridges.The main bridge of the Guanting Reservoir Bridge with the length of main span 720 m is analyzed as a background example,basing on static and dynamic analysis of original structure,the scheme of waffle deck using UHPC(Ultra High Performance Concrete)in place of traditional deck using normal concrete is put forward.Then the effective width method for flexural capacity of UHPC waffle deck panel is proposed.The main work of the thesis is as follows:1.The simulation analysis method of suspension bridge in completed and construction phases is described,the reasonable completed bridge state and suspender state of suspension bridge are calculated,and the simulation analysis of the saddle pushing process is carried out.In the end,the parameters affecting the non stress length of the main cable are analyzed,and the adjustment of main cable bolt is given.The scheme of lightweight composite girders with waffle slab instead of normal concrete deck panel is proposed.The finite element analysis of the local model and the whole bridge model are built and analyzed basing on the lightweight composite girder scheme,and the static and dynamic results are compared with traditional composite girder scheme.2.The ANSYS finite element software is used to establish the model of traditional composite girder scheme of completed bridge and during construction stage.Then the flutter stability of bridge with the methods of stiffening deck construction of the integral hoisting and separated hoisting construction is compared and analyzed,and the dynamic characteristic influence parameters of flutter stability is analyzed.In addition,the effective vibration suppression measures during erection are proposed.Finally the flutter stability during construction stage of light weight composite girder bridge is analyzed.3.An effective width method for flexural capacity of UHPC waffle deck panel is proposed.Firstly,3 sets of test data of UHPC flexural members are used to verify the ANSYS finite element method.Then the finite models of waffle deck panel are established to investigate the influence of effective width of waffle deck panel with several parameters.Finally,the formulas of effective width method for calculating the flexural capacity of waffle deck panel are derived by using the elastic-plastic theory,and the correctness of the formulas is verified.