Research On Key Issues Of Construction Control System Of Long-Span Cable-Stayed Bridges

Based on the related researches at home and abroad, problems in construction control system, parameter identification and prediction method for structure behavior of cable-stayed bridge with kilometer span have been systematically studied, wherein, traditional control methods can not satisfy the control accuracy of large span cable-stayed bridge. The work presented in this study focuses on several aspects of the following:1. The whole process control method based on geometric control is studied in view of relevant researches in domestic and overseas, moreover, it is applied to the construction control of thousand-meter scale cable-stayed bridges.2. Comprehensive sensitivity analysis on parameters inducing construction errors during the whole construction process is carried out, and the main parameters and their influence scope are determined according to the analysis results, which will have certain significance in theoretical calculation and construction control for cable-stayed bridges.3. Combining gray neural network and finite element method, an optimized inversion algorithm is proposed for the construction control of thousand-meter scale cable-stayed bridges. Then, parameter estimation and identification are addressed on the relevant structural parameters involved in the process of construction control. In term of the results of synthetic identification on multi-parameter, the structural calculation model is modified and the control process of subsequent construction is also guided. This kind of method has a higher accuracy result comparing to the traditional ones, and will ayoid the error of local optima, wherein the sample databases are relatively less.4. A hybrid approach combining D-S evidence theory and gray neural network is put forward to predict the errors related to construction control of thousand-meter scale cable-stayed bridges. Error processing method is proposed to the one exceeding the scope of errors allowed during construction control. Then, the mechanism of errors occurred, the treatment for errors and the impact of errors are elaborated in detail. Besides, the correctness and feasibility of the theory proposed in this paper is verified, with the data examples of actual control process.5. Construction control database system for thousand-meter cable-stayed bridges is established. On the basis of the whole construction process control system, data processing solutions for control system of geometric control method is proposed, to meet the requirement of parameter identification and structural state predicting to data completeness. And during the process of identifying and predicting, the sources of error and error accumulation in structural component manufacture and installation are considered, therefore, the factors influencing control process will be taken into account comprehensively.6. For construction control of large segment beam of cable-stayed bridge, an error control method is proposed based on the optimization method. And a mathematical model for structural optimization problems is established, with considering errors generated in the process of beam manufacture and installation. Furthermore, with the purpose of reducing the error of the final bridge state, researches on progressive control and correction for subsequent construction phases of structures are studied, by employing multi-objective and multi-constrained optimization method.