Research & Development Of Health Monitoring And Assessment System Of Wenhui Cable-stayed Bridge

More long-span bridges have been built with the rapid development of the human society, civil engineering techniques and communication, more attention has been drawn to the safety, durability and normal functions of these bridges. Health monitoring systems and intelligent control technologies have been introduced into these long span bridge and are developing rapidly, which makes health monitoring becoming an active domain of academe and engineering all over the world.In this paper, the Health Monitoring and Assessment System of Wenhui Bridge was developed based on summarizing and studying bridge's health monitoring and assessment technologies in world, as well as the features of long span PC cable-stayed bridge.In the section of structure damage identification of this paper, a structure damage identification method based on measured data of static displacement and FEM was put forward. Compared with the method of dynamic damage signatures, this static method produced higher degree of accuracy. Its effectiveness was proved by numerical damage simulation.Based on using elementary ideas of the latest theories with the combination of extensive achievements of bridge condition assessment and the other correlative domains, the assessment model was established using analytic hierarch process and variable weight synthesizing, which evaluated PC cable-stayed bridge's condition in service by grading items in bottom level of assessment model.According to the problem in cable tension monitoring that the damper set on cable will reduce the accuracy of cable tension measurement, an updating method was advanced to identify the computational cable length through the theoretical cable tension. And then, the relatively reliable measured cable tension could be obtained.To the problems in long-term monitoring of concrete stress, the numerical simulation for concrete creep effect of the main girder segment of Wenhui Bridge was made; accordingly a method that can approximately separate the creep strain was put forward.The monitoring database of Wenhui Bridge was designed and established basedon the hierarchical assessment model mentioned above. According to the user demands on database operation, the software interface of this assessment system was designed and developed preliminarily.