Study On Mechanical Principle And Mechanical Properties Of Large Truss Arch Bridge

Arch structure is mainly subjected to compression,which has the advantages of high bearing capacity,clear force and high stiffness,but its crossing capacity is restricted by its stability.The truss structure is mainly tension and compression of members.The stress system is simple and the combination forms are various.By reasonably arranging the members,the flexural and shear strength can be maximized,so that the strength of materials can be fully exerted.Aiming at the mechanical characteristics of two kinds of structures,a new arch bridge structure,large truss arch bridge,is proposed in this paper.Its structural characteristics are that the arch rib is used as the upper chord and the main girder is the lower chord.The web bars are only set up in 1/4 to 3/4 area,and the flexible suspenders are arranged normally,thus forming a large truss structure with flexible suspenders.The structure has the advantages of both arch and truss.In this paper,the structural form and mechanical principle of large truss arch bridge are given,and the mechanical properties of large truss arch bridge are studied in depth.The structural strength,stiffness,stability,dynamic characteristics and temperature response of large truss arch bridge are analyzed by finite element software modeling and compared with traditional arch bridge. At the same time,the mechanical characteristics of large truss arch bridge under different span and rise-span ratio are studied.The structure shows that compared with the traditional arch bridge under the same conditions,the overall stiffness of the truss arch bridge is greatly improved,and its stability and dynamic performance are much better than that of the traditional arch bridge.It has good adaptability under different span and rise-span ratio.Finally,the test design of 500-metre truss arch bridge is given.Large truss arch bridge has high stiffness and stability,and its dynamic characteristics have been greatly improved.At the same time,it has clear force,ingenious conception,simple and convenient construction,and reasonable cost.It has good application value under suitable terrain,geology and hydrology conditions.It is a new competitive bridge type,especially for high construction.Railway bridge,long-span,super-long-span arch bridge.The new structure system provides a new and effective way to improve the rigidity and break through the bottleneck of stability of arch bridges,and has great engineering application prospects..