Control Method Based On Gray Theory Of Large Span Cable-stayed Bridge Construction, Research And Applications

Cable-Stayed Bridge is a kind of composite structure composed of three basic components of cable, tower and beam. Modern cable-stayed bridge takes up an extremely important position in the structures of contemporary bridge engineering with its excellent structural function, spanning capacity and graceful style. In recent 50 years, rapid progresses have been made due to modern structural theories, high-strength material, computer technology and the improvement of construction technique and technics. The augment of the span in cable-stayed bridges push forward the development of theories on the analysis and design of structure engineering, which has become a significant subject involved in the study of construction control theories of large-span cable-stayed bridges.Based on the grey system theory, and then combine with the construction characteristics of cable-stayed bridges and feedback control method, this paper takes the cable-stayed bridge under construction as the interferential grey technology system with physical prototype and analyzes the random process as grey process in line with grey system theory. On the condition that other factors are controlled effectively, GM (1,1) grey model is established by taking installation-elevations of main girders and cables' tension as two control inputs of system during the construction of the cable-stayed bridge. The objective of "dual control" on both the bridge configuration and cable tension can be achieved by means of analyzing the feedback information, mending GM (1,1) model promptly and predicting the installation elevations and the cable tension of next construction stage.Grey system theory is applied to the construction control of Shaximiao cable-stayed bridge on the expressway from Chongqing to Hecuan in this paper. Judging from the outcome of the control on this accomplished bridge, Grey system theory can be well applied to the construction control of cable-stayed bridges. Moreover, some random variables can be properly predicted during the process of the construction of cable-stayed bridge by using GM (1,1) model.