Practical Computation And Analysis Of Endogenic Force Of Through Composite Arch Bridge

Beam-arch association bridge is one kind of new combination bridge system, in which the arch ring and beam is connected by the suspension bar, sharing the load. It puts beam and arch all together, not only demonstrate the beam bridge and the arch bridge respective characteristic, but also enable two kinds of bridge's merits to obtain the supplement mutually. The arch which main bear pressure and the lane beam which main bear bending moment and horizontal force are combined to share the load, so it can display each combination component and the material function fully, then it may save the needed materials, reduces the construction cost. The arch rib thrust force is balanced by the pre-stressed tie beam, and the superstructure does not have or only has very small horizontal thrust on the substructure, it has low requirement to the foundation. Therefore, Girder-arch bridge is adopted widely in the actual bridge construction. The girder-arch bridge is one kind of new bridge structure pattern, it is very essential to carry the analysis and computation research of internal force because of its particularity and the complexity.This paper first analyzes and computes the internal force equations of hingeless arch in cases of horizontal displacement, the rotational displacement and uniform load with rectangular coordinate system, then derive the rotational displacement equation for parabolic arch, and it was checked by finite element software Midas/Civil. Then through the analysis of the suspension bar's transmission performance, distribute the uniform load affecting on main girder to the arch rib and beam, and by using displacement method, apply rigid arm on skewback, use the derived the rotational displacement equation and the rotational displacement equation of fixed beam to compute the internal forces of composite system bridge, and check the formula. Finally use elastically supported continuous beam method to calculate transverse distribution factor of the beam and arch combined bridge, a comparative analysis of example carried on. It also carries on the parametric analysis separately to the influence coefficient in the formula, obtains the general law, which not only has theoretical significance to internal force calculation and study of arch bridge, but also has practical significance to engineering practice.