Construction Control Research Of Steel Truss Stiffening Girder Of Suspension Bridge

NaZha Bridge is the third group implementation project that Henan Province aids Jiangyou City, Sichuan Province after earthquake, designed as a double twins single span suspension bridge with steel truss stiffening girder, exemplified in Qian Yuan mountain scenic spot of Jiangyou City, and is the important bridge in connecting Sichuan provincial highway S302 and the direction of Qian Yuan mountain. Based on the actual construction circumstance of NaZha bridge, the paper mainly studies the construction monitoring of NaZha bridge. The main jobs as follow:1. Establish the whole construction process calculation models of NaZha bridge by the finite element software "Midas/Civil", revise these models according to the material properties used actually in bridge,construction error and boundary constraint conditions, analyse the whole construction of NaZha bridge on the basis of the models, and provide theoretical guidance for construction monitoring of NaZha bridge.2. Formulate the construction monitoring -scheme for NaZha bridge and guide the construction monitoring of NaZha bridge.3. Though follow-up monitoring and controlling the main towers construction of NaZha bridge, forecast the following construction of the main towers;Analyse the stability of the builded main towers, get the initial condition of the main tower in naked tower stage, and provide convenience for the following constructions of main cable erection steel truss stiffening girder erection and the main cable saddle pushing construction。4. Systematically analyse the construction affecting factors for main cable erection, make out the impact relationship between the midspan win of the main cable and the factors which include the length change of the main cable without stress,temperature changes,span changes,the value of pre-taking up and so on, and guide the main cable erection of NaZha bridge.5. Study on erection methods of steel truss stiffening girder, demonstrate that using cable hoisting method for steel truss stiffening girder erection is rational, and analyze the erection method's influence to the structure stress of NaZha bridge. Study on connection styles during the construction of steel truss stiffening girder, get out that the erection of steel truss stiffening girder of NaZha bridge should adopt the hinge and rigid hybrid connection, and make out the setting hinge scheme which is suitable for the construction of NaZha bridge. Study on closure methods of steel truss stiffening girder, conclude that NaZha bridge should adopt the loading construction method in midspan for the close construction of steel truss stiffening girder, and though analysing the temperature's influence to the closure construction of steel truss stiffening girder of NaZha bridge, guide the construction of the bridge.6. Though the whole process monitoring and predicting for the main cable saddle pushing construction of NaZha bridge, determine the pushing time and the pushing quantity scientifically and reasonably, and provide security for steel truss stiffening girder erection and bridge deck pavement construction.This thesis research gets funding from the project"The overall scheme research on bridge health monitoring and damage diagnosis" of outstanding talents projects of Henan province(-the project Numbers:084200510003).