Study On Dynamic Monitoring System For Deformation Of Masangxi Yangtse River Bridge

The Masangxi Yangtse River Bridge is a long span cable-stayed bridge with two towers, as one of two important projects of Chongqing circular high-speed highway. Therefore, it can be of realistic significance to monitor its safety status when it works. And deflection and deformation monitoring of the cable-stayed bridge is always of importance for bridge safety monitoring, but, at the present, there is almost no auto-measurement of deflection or deformation which can be directly used for displacements of the cable-stayed bridge, so it is very be of important practical significance to develop a set of deflection and deformation auto-measurement.The thesis refers to study work as follows,①To expound important significance of bridge safety monitoring, and analyze the importance of deflection and displacement measurement for bridge safety monitoring. With the introduction of all kinds of auto-measurement process at home and abroad, it is very necessary to carry out study on dynamic deformation measurement of the Masangxi Yangtse River Bridge.②To discuss in details all kinds of auto-measurement at home and abroad from such aspects as principle, accuracy, advantages and disadvantages. With discussion of their defects in measuring deflection and deformation of the Masangxi Yangtse River Bridge, the imaging measurement is chose as technology project as a whole.③On the basis of study on imaging measurement principle, the self-calibration imaging measurement is brought forward. In the following, to do the work of design for optical system, self-calibration imaging system of deflection measurement for single point comes true. Then in terms of distributing features of measurement points, the synchronous dynamic measurement for multi-point is accomplished. With the analysis of relevant factors influencing real-time measurement, the strategy to improve real-time measurement is put forward.④On the basis of features of tower structure, the defects of measuring deformation of tower with self-calibration imaging are carried out, then dual-laser imaging measurement principle is put forward. After designing its optical system, the measurement system for tower deformation is achieved. Finally, both deformation measurement and deflection measurement system are arranged into one measurement system, and system is designed as a whole from both hardware and software.⑤To do experiment of self-calibration imaging measurement to verify its resolution, accuracy, range and dynamic real-time. And to carry out the experiment of dual-laser imaging measurement to test its excursion. At last, the discussion of measurement result is carried out.By the contrast between measurement result and theoretical valve, it is true that both the self-calibration and the dual-laser imaging measurement system can come up to required accuracy, resolution, range and real-time.