The Static And Dynamic Analysis And Research Of Of Xiangjiang River Sanchaji Self-anchored Suspension Bridge

Sanchaji bridge which locates by the Xiangjiang River in Changsha, Hunan province, is most maximum span paired-tower three-span self-anchored suspension bridge completed in the world . Based on the project of Sanchaji self-anchored suspension bridge, this thesis establishes integrated whole bridge three dimension finite element model by using the large-scale finite element computation software MIDAS/Civil, and analyzes the reasonable design state, and do static and dynamic analysis of Sanchaji self-anchored suspension bridge, etc. The main contents and the conclusions are followed:Firstly, this thesis obtains the reasonable design finished state of the sanchaji self-anchored suspension bridge by utilizing the suspension bridge modeling simulation assistant which MIDAS/Civil provides, then gets three dimensional coordinates of geometry of the main cable's every node which is under dead load, and gets unloaded cable shape by using the finite element reverse analysis procedure in order to provide the reliable data for the location of datum strand and the host saddle. It is possible to simulate the geometrical non-linearity prominent suspension bridge construction procedure well by using the large-scale finite element computation software.Secondly, through establishing integrated whole-bridge 3D FE model, the thesis analyzes the bridge structure response to the dead load action, the traffic lane load, the temperature action, other variable actions and the combination for action effects. It is concluded that the stiffening girder is compressed basically and primarily, and the moment internal force is quite small because of the main cable horizontal component function in finished state of this bridge. Under the vehicle and crowd loading, the main span cross reaches 30.9cm down-warping, the biggest pylon deviation reaches 8.54cm, and 1.59MPa tensile stress appears in the pylon. Under the function of sunshine non-uniform temperature field, and there is 3.01MPa tensile stress in the pylon, so the sunshine non-uniform temperature action becomes the static load operating case of controlling design of the pylon of Sanchaji self-anchored suspension bridge.Thirdly, the thesis analyzes the self-vibration characteristics of Sanchaji self-anchored suspension bridge, studies mechanical characteristics of this bridge according to the computed results, and provides the preliminary conclusion for the wind, the earthquake resistance and the stability analysis.Fourthly, the thesis studies this bridge earthquake resistance performance by using time-history dynamic method. The fitting artificial seismic wave is inputed to the 3D FE model in three kind of load cases: horizontal+vertical,transverse+vertical and vertical. Then dynamic response value of this bridge key point (section) such as the internal force or the displacement can be obtained. The results tell us that the vertical seismic wave influence don't allow to be neglected. Meanwhile, the thesis compares with two models, one of which is under heavy pressure mass, and studies the influence of heavy pressure mass on bridge dynamic performance and the entire bridge earthquake resistance performance. The result shows that it can change the response peak value and the response-time point, even change the entire time-history response course of some response value. These conclusions can provide the reference for similar bridge design.