P. C. Cable-stayed Bridge, The Control Of The Whole Construction Process

Taking Xiantao Hangjiang Highway Bridge as the project background and based on other domestic or foreign cable-stayed bridges, a deep study on the whole process of the construction controlling of cable-stayed bridges is carried out in my paper. At the Beginning of the selection of two controlling methods, the Gray Theory and the Kalman Theory these two ways, which are always used in the controlling of Cable-stayed bridges, are then introduced and compared with one another. At last, the Gray Theory combined with forecasting control is adopted to control the real construction. The controlling model was built so that the effect on the beam stress, elevation and cable tension which are caused by some important factors such as beam deadweight, cable tension error, temperature, shrinkage and creep of the concrete and so on can be analyzed to make sure how to control these important factors during the construction. The measuring ways of key factors are also emphasized and the parameters should be adjusted according to the measuring result of deformation, strain and cable tension, which are totally called "Three factors" in this paper. In the measuring of "Three factors", the content and the approach are introduced one by one and some new and better way are put up with in this paper. Through the practicing, the new ways are proved to be available. Moreover, the influence of temperature is analyzed. And the influence of sunshine temperature difference is decreased as low as possible. At the finishing of this paper, the effective identification of designing factors is done and the setting elevation and the cable tension force in next stage are forecasted according to the situation of finished beams. Through the forecasting, the constructing state is in coincidence with the designing state.During the bridge construction process, the value of designing parameters are made close to the construction state by means of data collections, optimal controls and detailed analysis of different reasons that caused errors. Taking grasping today and predicting the future into consideration, the constructing faults have possibly been avoided. As a result, the working capacity of the adjustment of the cable force has been decreased and the labor days have been shortened. Due to some improvement of measuring methods, the measuring accuracy and the measuring results have obviously been upraised. Finally the error of the line shape and the cable force at finished bridge state has been controlled in an ideal limitation.