Trial Designing Study of Half-through Arch Bridge with Main Span of 1 000m

Abstract:

The arch bridge stability declines when the span increases. The phenomena such as shearing and bending deformation tend to happen with moving load. Put the rigid bar between the main girder and arch rib to form a triangulation network， and then the triangulation network， arch rib and main beam compose a continuous series triangles. The stability of the triangle is used to improve the linear stiffness of the main beam and arch rib， so as to improve the overall stiffness of the structure. When the bridge is under moving load， the triangle must be subjected to the non-node load， which reduces the stability of the triangle. Therefore， suspender and columns are set to increase the elastic constraint and reduce bending and shear deformation between nodes. In addition， integral nodes can be used to simplify the structure with the proposed method of precast-assemble for construction which is convenient and fast . The concrete structure of the scheme is given， the mechanics principle is expounded， and the trial designing of half-through arch bridge with the main span of 1 008m is carried out. The finite element results show that the strength， stiffness， stability and dynamic characteristics of the presented arch bridge meet the requirements with a better mechanical properties than traditional arch bridges and proposed design is more economical.

Key words:stability of the triangle;half-through arch bridge;stiffness;finite element;trial designing