| In order to solve the problem of fast adjustment of cable force in the completion stage of cable-stayed bridge,a method of cable force adjustment based on specified stress is proposed.The inelastic contraction amount is introduced for each cable element,which together with the conventional node displacement constitutes the basic unknown of the cable element.In the element equilibrium equation of the cable element,the right end term corresponding to the inelastic contraction amount is the cable force.In the finite element equilibrium equation of the full bridge,the cable force of each cable becomes the right-end term corresponding to the inelastic contraction amount of the corresponding cable.Thus,the finite element equilibrium equation with the conventional displacement and inelastic contraction amount of the cable as the generalized nodal displacement vector and the conventional nodal load and the cable force as the generalized nodal load vector is obtained.By using the full bridge finite element equilibrium equation of the cable-stayed bridge with the inelastic contraction amount,it is possible to solve the overall equilibrium equation at one time under the condition that all cable forces are specified,the target inelastic contraction amount of the cable minus the initial inelastic contraction amount is the cable adjustment amount,so that all cables can accurately reach the target cable force from the original cable force.In order to solve the problem that only part of the cable force is adjusted to meet the cable force requirements of the entire bridge in actual construction,an optimization model is proposed that uses the inelastic contraction amount of some cables as the optimization variable and the cable force difference of all cables as the objective function,and the corresponding calculation formula was derived.The example demonstrates the feasibility and effectiveness of the full bridge and partial cable adjustment algorithm. |
PDF Full Text Request