Construction Control of Long Span Suspension Bridges During Erecting Stiffening Girders

It is important to carry out the construction control calculation before erecting stiffening girders and the monitoring during erecting the girders for controlling the long span suspension bridges.In order to eliminate the influence of the construction error taken place in the construction of the main cables on the construction of stiffening girders,and to ensure that the deck line shape agrees with the design line shape,a feedback control method is brougt forward.The theoretical values of the controlling parameters and the free slipping values of main saddles are calculated by the finite element method.On the basis of the slipping curves and the resistance to bending of the towers,the time and the value of pushing the saddles are determined.Through the construction control of Yichang Yangtze River Bridge,the variation regularities of the height of the main cables,the slipping of the main saddles and the opening angle values of stiffening girders are obtained.At the same time,the safety of the structure during construction is guaranteed and the line shape of the deck conforms to the design specification after the erection finished.