The Control And Simulation In Construction State Of A Big Span Cable-Stayed Bridge

With the employment of high strength material, improvement of structural analysis, and development of construction ways, it is a rapid developing period for cable-stayed bridge in the 90's,20th century. But the cable-stayed bridge is an indeterminate structure with high degrees, and the design objective has relativity with the process of construction, especially the constant conversion of the structure systems, and consequentially which will bring large influence of complicated internal force and displacement to bridge structure in the construction phases,these features enable the analysis and controlling in construction state of cable-stayed bridge to important research project. In this paper, based on studying and summarizing the research work of former scholar and YunYang ChangJiang Bridge, the imitation of the construction control of cable-stayed bridge; taking BP nerve network basic theory as its theoretical basis, a prediction model of construction control is established, which is verified feasible in the construction control of cable-stayed bridge.Firstly, based on construction controlling both domestic and abroad in the construction state on cable-stayed bridge, the system of construction control of cable-stayed bridge is discussed and analyzed. The chief problem of the construction control of cable-stayed bridge is making certain the theory, content, principle, and measure. At the same time the bridge is imitated, and taking the imitation result as theory track of the construction control. So, the parameter identification methods, the gray control system, the kalman filtering methods and adaptive control methods were summarized from the point of construction control methods that were used in the project. Forward-calculation method and back-running method and no-stress method are methods, which are used at the construction control of cable-stayed bridge. All the factors of construction state deviated ideal design state are discussion, which are valid control for the process of construction.Secondly, aiming at YunYang ChangJiang Bridge, GQJS was used to set up the plane model of this Bridge, which is simulated and analyzed in the construction stateof the cable-stayed bridge. In the process of construction state, the imitated measure of structure component is discussed and the plane model is analyzed on the construction feature of the cable-stayed bridge. At the same time, the result of the imitation is labored and compared with the data of each construction phase from the building site, and the change rule and influencing factor of all the parameter in Forward-calculation for cable-stayed bridge construction control are summarized, which has high reference value for similar cable-stayed bridge.Finally, the construction control of cable-stayed bridge based on BP neural networks is discussed and analyzed. It is introduced the basic theories of artificial neural networks in brief in this process, and BP neural networks, and BP algorithm and bring forward some valid methods on the main drawbacks of slowly learning convergent velocity and easily converging to local minimum of the Backward-propagation (BP) networks in this paper. On this foundation, taking the YunYang ChangJiang Bridge as an example, with setting up the construction model, analyzing the simulation result, and comparing with the matter-of-fact result, the application of the neural network method in the construction control of cable-stayed bridge is demonstrated possible.