Stress Analysis And Experimental Verification Of Special-Shaped Concrete Filled Steel Tube Arch Bridge

With the development of China’s urban construction,the requirement of Bridge structure aesthetics is increasingly high.So the special-shaped steel tube concrete arch bridge which owns both beauty and utility is put into application. Shaped structure also brings some problems of structural analysis. Due to lack of sufficient experience in the design and construction to this kind of bridge, it is necessary to carry out appropriate research works.The Dadu River Bridge with the span of120m which is located in Shimian Sichuan Province, is taken as an example in research works. A full-bridge analysis model and a local analysis model to key parts of the inclined leg is established by software MIDAS CIVIL and ANSYS. The overall and local performance of the bridge have been studied by load tests. The main research work and conclusions are as follows:Firstly, the three dimensional finite element model of the full-bridge is establishing with MIDAS/Civil, the rib stress and deflection in construction stage and the operational stage have been analyied. At the same time,design calculations have been done to primary and secondary rib,crosswise beams,suspension wires and main beam,showing that the results are in accrodance with design requirements.Also,the influence to deflections and stresses in rilos duced by concrete creep in tube are stuied.Secondly,the load tests have been carred out to the special shaped steel tube concrete arch bridge to analyise the comparatively theoretical dates and experimental dates of rib,main beam,suspension wires. It is verified that the working conditions and the load carring capacity meet the design requirements.Thirdly,the local stress analysis to lug, abutments and oblique legs which cannot be analyzed through overall model,has been carred out,showing that the structure meets design specifications. It is concluded that the performance of the abutment and oblique leg rib are good,The tensile and compressive stresses are less than design values according to the material design strength. There are stress concentrations in the junction areas between abutment and oblique leg,abutment and beam,the conner of the abutment and rib where the tensile stress values are high.So it is necessary that some steel plate or reinforced steel bars would be increased to decrease the stresses.