| Because of the advantages of small self weight,strong span,fast construction and beautiful appearance,steel box girder bridge has been widely used in municipal roads.Due to the complexity of urban road traffic network and the large flow of people and vehicles,the stress characteristics and stability of the bridge should be considered in the new bridge construction.In this paper,a continuous steel box girder bridge in Guizhou Province is taken as the research object.Midas civil,SOLIDWORK,ABAQUS and other finite element software are used to carry out numerical simulation of the bridge.The main girder hoisting,system transformation and other works in the construction stage of the bridge are analyzed.The static and dynamic characteristics of the structure,linear stability and nonlinear stability of the steel box girder are studied.The research contents can be summarized as follows:1.The development and research status of steel box girder bridge at home and abroad are collected and sorted out,and the mechanical characteristics of steel box girder bridge are described,further indicating the development prospect of continuous steel box girder bridge in China.2.Introduce the calculation method and analysis steps of finite element analysis,summarize the nonlinear finite element theory and common stability problems used in the calculation of continuous steel box girder,determine the finite element analysis method and suitable theory used in this paper,and briefly introduce the modeling process of beam element model and shell element model used in the numerical analysis.3.Establish beam unit model to simulate the construction process of steel box girder,discuss the internal force,stress and linear influencing factors of the bridge in the construction stage,and verify the feasibility of cantilever hoisting construction of small section bridge deck;in the bridge operation stage,mainly study the static characteristics of continuous steel box girder undermoving load,temperature load and dead load,and discuss the key points in the operation of continuous steel box girder bridge It is found that the influence of dead load and moving load is much greater than that of temperature.4.Through the analysis of the natural vibration characteristics and response spectrum of the continuous steel box girder,the natural frequency of the steel box girder bridge is obtained.Colleagues found that the horizontal response spectrum stress of the continuous steel box girder bridge is larger than that of the vertical,and the time history stress of the seismic wave is smaller than that of the steel box girder.5.The shell element model is established to analyze the linear and nonlinear stability of steel box girder,and the influence of stiffener spacing,stiffener form and stiffener thickness on steel box girder is obtained. |
