Analysis Of Arch Structure Of Top-mounted Steel Tube Concrete Arch Bridge Based On Arch Seat Displacemen

Since the first concrete-filled steel tube arch bridge was built in China,concrete-filled steel tube arch bridge has developed rapidly,with its maximum span exceeding 500 meters,and the number of concrete-filled steel tube arch Bridges under construction is also the largest.Among them,concrete-filled steel tubular arch bridge with upper bearing has strong competitiveness in mountainous and canyon terrain,but this type of bridge has high requirements on the arch foundation.The mountainous area of Guizhou is mostly karst landform,and the arch seat is easy to shift when the foundation is not treated properly.In addition,one of the reasons affecting the development of this type of bridge is the weight of the arch structure,and a reasonable arch structure can reduce the self-weight of the structure and improve the bearing capacity of the structure.Therefore,this paper takes a 450 m up-bearing concrete-filled steel tube arch bridge in Guizhou as the supporting project,and considers the influence of arch seat displacement on this type of arch bridge.The structural form of the over-arch structure is analyzed and studied.The main contents are as follows:(1)The general situation of the development of concrete-filled steel tube arch bridge at home and abroad is introduced,and then the relevant theoretical calculation methods of concrete-filled steel tube arch bridge are described by collecting data,and the arch structure form is analyzed.(2)Based on engineering hydrogeological data and relevant literature,analyze the causes of arch seat displacement and the types of arch seat displacement.Then,finite element models with different displacement types and different displacement amounts are established to simulate the arch seating displacement of arch bridge and explore the influence of arch seating displacement on the structure of arch bridge.(3)Combined with the influence of arch seat displacement on the arch bridge structure,carry out the analysis and research on the structural form of the bridge path system and arch column,analyze the influence of different arch structure parameters on the arch bridge structure under different displacement types and different displacement amounts,and obtain the arch structure form that makes the displacement,stability and static and dynamic characteristics of the bridge structure more reasonable.A new structure form of arch column is put forward.(4)Midas Fea NX 2022 finite element analysis software was used to establish a local model of key parts of the arch structure of the concrete-filled steel tube arch bridge with upper bearing.The stress of key nodes was analyzed to ensure the safety of the bridge structure and provide relatively reliable technical basis for the structural design and maintenance of similar Bridges in the future.