The Structural Design And Analysis Of Urban Light Bridge

With the rapid development of China’s economic construction and the promotion of urbanization,the problem of urban traffic congestion is becoming increasingly serious.In many large and medium-sized cities,the problem of traffic congestion has become a major factor restricting the development of cities.In the congested vehicles,small vehicles account for the main body of all vehicles.Therefore,if we can effectively separate small vehicles,we can greatly reduce the congestion in the city.For this purpose,we put forward the concept of light bridge in the city.Urban light bridge construction is limited to small vehicles,does not occupy the existing urban road resources,rapid environmental protection,can be regarded as an effective way to solve urban road congestion,the main research contents are as follows:Firstly,this paper summarizes the development of continuous steel box girder bridge at home and abroad and the characteristics of urban steel box girder bridge.Then it explains the significance of light bridge to alleviate traffic jam.According to the design concept of light bridge,referring to the existing steel bridge specifications,combined with the characteristics and requirements of light bridge,the structure design of light bridge is carried out.The finite element model of the whole bridge based on the plate shell element is established by using the finite element software.Through the calculation of the plate shell element model,the stress and deformation of the whole bridge in the operation stage are analyzed in detail.According to the stress characteristics of the light frame bridge,the opening and weight reduction design of the light frame bridge is carried out.In addition,the dynamic characteristics of light frame bridge are studied by dynamic method,and the first 20 modes of light frame bridge are calculated by block lansos method,and the first five natural vibration frequencies and vibration modes representing the vibration characteristics of light frame bridge are mainly analyzed,which provides theoretical basis for the study of seismic resistance and shock absorption of light frame bridge.The seismic analysis of light frame bridge is carried out by using time history analysis method.The nonlinear stability analysis of light frame bridge in operation stage is carried out,and the ultimate buckling load of light frame bridge is obtained.Through the research,it can be seen that the design concept of light frame bridge is basically feasible.Through the calculation and analysis,it can be seen that the light frame bridge can meet the requirements in static,seismic and nonlinear buckling stability analysis.