Cable Force Analysis And Stability Study Of Concrete-filled Steel Tubular Tied Arch Bridge

With the continuous development of China's transportation industry and the increase in infrastructure investment,especially the rapid development of high-speed railways in recent years,Concrete-filled steel tubular tied arch bridge(CFST)plays an important role in the construction of transportation infrastructure because of its beautiful appearance,light weight,large span capacity and low requirement on foundation.Concrete filled steel tube tied arch bridge belongs to the composite system of beam and has high internal statically indeterminate.When the hanger is tensioned,the tension of the hangers affects each other,And different tensioning schemes,different internal forces of the bridge structure.Therefore,the study on the cable force of hangers in this kind of bridge construction has great practical significance.Taking a 64 m concrete-filled steel tubular tied arch bridge in Qinghai as an example,this paper establishes a bridge model using MIDAS/ CIVIL,simulates the bridge construction stage.The main content of the article includes the following aspects:(1)Through data review,the history and current situation of concrete filled steel tube bridge and its materials are reviewed..(2)The numerical analysis model of 64 m CFST bridge beam is established,and the procedure and process of hanger tension in construction stage are simulated.The rigid support continuous beam method,unknown load coefficient method,and the rigid boom method were used to calculate the cable force.Three forward-reverse analysis methods were used to determine the construction force under the next and two tensions of the six tension sequences.Through analysis,it was found that multiple forward-reverse analysis can significantly reduce shrinkage and geometric nonlinearity.Finally,cable force closer to the target cable force.(3)Compared to the two kinds of tension scheme,the stress of arch rib concrete and steel tube,under two batches of tension,the construction cable force is smaller than that under one tension.The stress fluctuation of two tensioned arch ribs decreases obviously,and the stress is more gentle.(4)Based on the theory of structural stability,the stability of the bridge under the five load conditions during the construction and operation phases was analyzed,and the influence of the wind bracing on the stability was discussed.