The Simulation Analysis Of Multi-pylon Cable-stayed Bridge Construction Process

In order to clearly study the mechanicall behavior of multi-pylon cable-stayed bridge, the thesis is based on Jiashao Bridge, and analyzed the constructing process of the multi-pylon cable-stayed bridge with four cable plane and single column six-tower by way of nonlinear simulation. Finally it studied the parameter sensitivity, and it is the aim of this thesis.Firstly, it introduced the development of multi-pylon cable-stayed bridge, and discussed the geometric nonlinear analysis of cable-stayed bridge theory and methods, then detailed the effects of cable sag, beam-column, large displacement and its solution, while introduced the methods of calculating on concrete shrinkage and creep in new Highway bridge code, and methods and theories of calculating the first kind of stability of cable-stayed bridge.Secondly, based on theories and methods above, it analyzed the constructing process of Jiashao bridge linked with its finite element model by way of nonlinear static analysis. Then, it compared the displacement, axial force, bending moment and stress of tower, the deflection, bending moment and stress of beam, the cable of tension in key constructing stage. It came to a conclusion that the structural strength and rigidity of Jiashao Bridge meet requirements. It also analyzed the first kind of the stability during the construction process of the bridge and the result is that the first safety factor in constructing process satisfied the safety evaluation criteria (higher than4).Thirdly, it compared the impacts on mechanical behavior of the structure by geometric nonlinearity and concrete shrinkage and creep. The result is that it is necessary to consider the impacts of geometric nonlinearity and concrete shrinkage and creep in order to make multi-pylon cable-stayed bridge’s shape and internal forces meet the design and the code requirements.Fourthly, it analyzed the impacts on multi-pylon cable-stayed bridge’s mechanical behavior by burden and live loads. The burden influences shape and internal forces of the bridge a lot, so it must strictly control the constructing process during its installation and implementation design. When the multi-pylon cable-stayed bridge was symmetrically loaded a live load, the response of the bridge’s mechanical behavior showed symmetry. When the the main span is loaded a live load, the span has large response of mechanical behavior, and a certain influence on the neighborhood span but a little influence on the farther span. When the live load moves from the bank side span to the river intermediate span, the response of mechanical behavior was gradually increased, and the affected area was gradually expanded. Finally, it analysed the parameter sensitivity of multi-pylon cable-stayed bridge’s structural behavior. It came to a result that the main parameter sensitivity is the weight of beam, the temperature of beam, the modulus of cable, the weight of rigid hinge and the burden.