Analysis Of Reasonable Cable Force And Unitary Stability Of A Dissymmetrical Single-pylon Cable-stayed Bridge

Dissymmetrical single-pylon cable-stayed bridge is ground anchored bridge, a kind of layout form of cable-stayed bridge that a part of cables are anchored on the main beam and the others are anchored on the gravity abutment, which apply to the situation that bridge location is under the limitation of topographical features and the main span is long but the side span is small.The paper takes a dissymmetrical single-pylon cable-stayed bridge as an example, based on the determination of reasonable cable force under dead load and analysis of unitary stability, has done following work:(1) Basic calculate methods for reasonable cable force under dead load are expounded and summarized, the reasonable cable force under dead load of the ground anchored cable-stayed bridge is calculated by the least bending strain energy method, which is achieved by the plane finite elemont software Ansys.(2) After determining the reasonable cable force, the unitary static analysis of the completed status of the cable-stayed bridge is carried on, and the distinctive features of ground anchored cable-stayed bridge are expounded.lt is state variable that the finite element model software Ansys optimized, the bending strain energy of the main beam or the bridge. And the distinctive features of cable force are described.(3) The finite element method of the first and the second kind stability problem of the cable-stayed bridge is expounded in this paper, and it analyzes the essential difference of stability problem, unstable criteria and the evaluation criterions about the stability of the cable-stayed bridge are discussed. At the same time, it take out computational method of stablility of the main beam,the main pylon,and the bridge.(4) The finite element model of the cable-stayed bridge is established by the spatial finite element model software Ansys, the linear buckling safety factors is calculated under three different states, and the most possible destroyed forms are pointed as well, after this, the bridge is evaluated that the degree of stability safety is sufficient during the construction stage and completed stage. At last, the influences of initial stiffness of cable force and sag nonlinear on buckling safety factors are discussed.