Analysis Of Broken Cable Risk Theory And Health Monitoring Method For Long Span Cable-Stayed Bridge

Since the 20th century, the bridge construction has made a breakthrough at home and abroad, and the size of the bridge construction is toward large, soft in form, complex development in founction.The large-scale bridge is a national economic lifeline, because of their huge investment and influential role in national economy making the security, the durability and the normal use function of the large-scale bridge get more and more attention, but the bridge structure's security problem continuously draws more and more attention of the academic circle and the engineering. With the rapid development of science and technology, the large-scale bridge health monitoring, safety assessment, life prediction and other bridge engineering issues in the modern bridge engineering field have become the hotspot. Bridge structural health monitoring technique combining information technology and mechanical theory become an ideal means that replaces the traditional method of artificial load test, due to the on-line fault diagnosis of bridge structure, early warning of the bridge structure's accident, So far, the bridge structural health monitoring always researches on two keys:the information acquisition and safety evaluation, having made some progress. Because the bridge engineering involves multitudinous disciplines and the structural health monitoring is very complex, there are many critical theories and methods still in the exploration.Based on bridge monitor and appraisal theory and technology at home and abroad and according to the need of structural characteristics and development of cable-stayed bridge, the system of health monitoring and evaluation management certain super-large bridge was established and fruitful researches were carried out on the several methods and problems involved in health monitoring system.of long-span cable-stayed bridge. The main works and innovation were as follows:1.Fusion monitoring, in-situ testing results, constructs the multiple projects of in situ monitoring of health diagnosis system, Based on the integral concept, Genetic simulated annealing algorithm, the partial least squares of causal analysis model and the optimal power linear combination causal analysis model and the nonlinear wavelet neural network combined causal analysis model.2.Carries on the cable-stayed bridge's broken cable risky theoretical analysis. According to the design of the large bridge Yongjiang size, application of large space "MIDAS" finite element software simulation calculation model is established, the space of numerical simulation study, broken cable injury situation of different lasso rupture structural properties of cable-stayed bridge. The analysis results of different position clear structure fracture lasso sensitivity can be used as a structural health monitoring and sensor monitoring content arrangement of reference. 3.According to the principle of practicality and reliability, determine the large-span cable-stayed bridge health monitoring system monitoring project, Including various sensor arrangement, data collection and analysis, the monitoring data's storage and management etc. Completed Yongjiang super-large bridge health monitoring system design and realization the cable forces monitoring subsystem, the main vibration monitoring subsystem, stress and strain monitoring subsystem, for large bridge health monitoring model established a demonstration.4. Exploring large bridge structure state comprehensive evaluation method:Research a new method of comprehensive evaluation of the bridge structure by monitoring data, on the basis of the basic ideas in the absorption and using existing achievements. Based on Bridges and other relevant fields assessment of the latest research, constructing the great bridge structure health diagnosis criteria and standards of the comprehensive analysis theory and method, draws up the bridge structure essential spot the distortion monitor quantity and so on multistage early warning control value.This research work for large bridge structural health monitoring and evaluation of the management system to establish a set of practical and effective solutions, and it will be for the further development of health monitoring system applied to provide more rich theoretical results.