Calibration of Initial Cable Forces in Cable-Stayed Bridge based on Kriging Approach

Abstract

Although optimization methods are useful in the preliminary design of cable-stayed bridges for sizing of components and getting optimal bridge configurations, further fine-tuning is invariably conducted in the detailed design thus affecting various sensitive properties such as the deck profile and cable forces. The zero-displacement method that adjusts the initial cable lengths repeatedly to achieve the design deck profile is both computationally intensive and prone to convergence difficulty. Therefore a calibration method is proposed based on a Kriging surrogate model built using the uniform design approach. Apart from establishing the relationship between the bridge deck geometry and the initial cable forces by statistical method, the Kriging model also obviates the need for a large number of repeated finite element analyses. A simple cable-stayed bridge is used to verify the feasibility and accuracy of the proposed method. In real-life cable-stayed bridges with many cables, a staged calibration is implemented so that the Kriging model is used to identify reasonable initial forces in the critical stay cables so that the zero-displacement method or similar can be used for further adjustments. Verification shows that this staged calibration can address not only the deck level tolerance but also the control of cable forces.