Construction Monitoring For PC Cable-Stayed Bridges

With increasing span length and structure complexity of a cable-stayed bridge, Construction control and monitoring plays an important note during erection of the bridge girder. The objective of construction monitoring is to find out the working state of the structure, especially the construction errors which may occur in the erection process. Then, necessary adjustments can be made timely. It is various that in order to ensure construction quality and structural safety, construction monitoring is one of the most important jobs. In this work, some important problems, i.e., measuring methods of cable force and stresses interior concrete are investigated and solved. This work has formed a basis for construction control of a long span PC cable-stayed bridge.As we know, in formulation of the frequency method for cable force calculation, effects of three parameters, i. e., the bending rigidity, the slap and the sag of cables are not being considered simultaneously. Although such problem can be treated by finite element method, it is not as simple as to use a formula. Thus FEM is not a best choice for cable force calculation during construction. Another problem is how to determine those parameter values for cable force calculation. In the present study, frequency method is further investigated and a new formula for cable force calculation is proposed. In this formula, the effects of the cable bending rigidity, the cable slope and the cable sag have been taken into account. So, the procedure is simplified. Moreover, methods for cable force calibration at the construction side as well as for the parameter determination are also proposed. The proposed methods have been proved to have very good accuracy for cable force measurement. Those methods have been successfully...