Geometric Nonlinear Analysis Of The Rib-hoisting For Long-span CFST Arch Bridge

Nowadays a lot of research work about the nonlinear effect have been done on the bearing capacity of arch bridge. But it is not enough to study the nonlinear effect in the construction process. This paper is concentrated on the geometric nonlinear static analysis of the rib-hoisting for concrete filled steel tubular(CFST) long-span arch bridges. And the rib-hoisting forecasting is given in real project-Nannidu Arch Bridge in Enshi.First of all,the nonlinear equation of structure is presented in this paper based on virtual work principle. It is thought that the Updated Lagrangian Formulation(U.L.Formulation) is more adapt for nonlinear analysis computer program for arch bridge. The concrete expression of the unit tangent line stiffness matrix is given.Secondly,a geometric nonlinear static finite element analysis program of cables,bars and beams is presented. An incremental iterative method based on the Newton-Raphson method is adopted here to solve the nonlinear equation. A calculation example is given to demonstrate the necessity of thinking over geometric nonlinear affect.Finally,in this paper progressive algorithm is thought to be reasonable to simulate the construction process of arch bridge. The program of the finite element considering geometric nonlinear condition has been made to analyze the construction process of rib-hoisting for Nannidu Arch Bridge.