Analysis Of Design Parameter Adaptability And Technical Economy Of Steel Plate Composite Girder Bridge

At present,China is in the process of promoting the construction of highway steel structure bridges and implementing the development of green transportation.The steel plate composite girder bridges are gradually applied in engineering,and the research is gradually deepened,because they can adopt light steel-concrete composite structure,factory production prefabrication and standardized assembly construction.Based on the research project of Shaanxi Transportation Department-steel plate-concrete composite girder bridge construction key technology research and engineering demonstration,this paper studies the mechanical performance and technical economy of the steel plate composite girder bridge with double main girder structure,small crossbeams in the span and vertical stiffening ribs in the web.The main design parameters are analyzed by finite element calculation.The reasonable range is obtained and the corresponding design suggestions are given.The main work and achievements are as follows:(1)The research status and development process of steel plate composite girder bridges are introduced,and the popularization significance of developing steel plate composite girder bridges in China is analyzed,and the general structure composition and standard calculation methods are summarized.(2)The finite element model of three-span steel plate composite continuous girder bridge is established based on the method of hole-by-hole erection.On the basis of calculating the mechanical characteristics of each construction stage,the technical characteristics of stress,deflection and steel quantity of double-girder steel plate composite girder bridge are studied.Based on this,the reasonable range and design suggestions are put forward from the number of main girders,the height of steel girders,the width of bridge deck,the size of lower flange plate,curvature radius and so on.The key design parameters including the number of main girders,the height of steel girders,the thickness of concrete deck,the number of small beams and the radius of curvature are studied by using the finite element grillage model.The influence rules and design suggestions of the design parameters on the transverse distribution of steel plate composite girder bridges are obtained.(3)The viewpoint that the amount of concrete,ordinary steel bar and steel per square metre and the cost of each square metre bridge are taken as the technical and economic indexes of steel plate composite girder bridges is put forward.By calculating the current situation of material consumption of 18 steel plate composite girder bridges in China,the mathematical expressions of the amount of three materials,self-weight and span are fitted,and the technical and economic comparison is made with the pre-stressed concrete girder bridges.The economic advantages of steel plate composite girder bridge are obtained.(4)Through theoretical research,the expression of economic beam height of steel plate composite girder bridge is deduced from two aspects of meeting the bending inertia moment of section and the stress requirement of steel beam.The life cycle cost of steel plate composite girder bridge is studied.By dividing it into three parts: planning and construction cost,operation and management cost and dismantling and recycling cost,the calculation model is established and the technical economy is evaluated.