Research On The Erection Plan Of Steel Box Girder And The Construction Process Of Three-Tower Suspension Bridge

Now the construction of three-tower suspension bridge is still in the initial stage, and the strong span ability of the three-tower suspension bridge has been favored by more and more people, but there still has been many problems needed to be studied in design and construction of new structure. This thesis analyzes the overall hoisting construction process of the stiffening girder, and studies construction scheme, the calculation method and influence parameters of the stiffening girder.For the hoisting process of stiffening girder of suspension bridge , it is necessary to make a fine simulation analysis for each hoisting working condition, but the method of the back running analysis has its limitations. This thesis has established a set of forward calculation method used in the analysis of hoisting construction of stiffening girder of long-span suspension bridge by use of tangent displacement method, and verifies the reliability of the method by use of numerical example.Aim at the schemes of erection from the middle of span to two towers and from two towers to the middle of span in the thesis, detailed finite element model is established with ANSYS based on the project background of Taizhou Bridge. The change rule of slits between lower limb of stiffening girders, the change rule of internal force of temporary connection, and the change rule of axial force of hangers, the main cable displacement and the inclination of main cable on the side of bridge etc are analyzed during the hoisting construction of stiffening girder. The construction plan recommended is to raise by comparative analysis.To the hoisting plan recommended ,the analysis model for overall construction process of the stiffening girder has been established by use of forward analysis method with BNLAS in the thesis. The thesis studies the influence of the line shape of erected bridge, axial force of hangers and the deviation of middle tower head etc caused by the parameter of temperature changes, sling length error, temporary load in construction etc and the hoisting of two asymmetric span, using the model established. Research results show that: To the three-tower suspension bridge of two span ,when erect the stiffening girder from the middle of span to two towers, the stress of structure is more reasonable . The hoisting construction of stiffening girder of big span suspension bridge can be simulated by use of a set of forward calculation method established with tangent displacement method.