The Model Of Bridge Tele-monitoring Appraisal System Based On Theory Of Internal Force's Envelope

Compared to the routine load monitoring system, bridge tele-monitoring currently and popularly leads the bridge research due to its safety, real time, continuity and in time alarming. At present, researchers have researched on and conducted dynamic finger print method (mode identification method), model modification and system recognition method, neuron-net method, and heritage computation method, but no systematic appraisal theory of the bridge tele-monitoring system has been established because bridges vary in such as indefinite factors as construction materials, structural components, working conditions, and testing signal. This paper, under the guidance of the instructor and after a 3-year research in the related field, attempts to present a bridge tele-monitoring appraisal system based on a theory of the internal force's envelope.The background of the bridge tele-monitoring system in China and its significance are presented especially, during the particular era in which the public are concerned about the high bridge construction speed, the quality problems arising in bridge construction, the increasing bridge operation traffic volume, and bridge safety.The principles and methods of the bridge safety appraisal system are introduced .On this basis,the general concept of the appraisal theory of the bridge tele- monitoring system based on the theory of the internal force's envelope is brought. The analytic results show that the above mentioned system is feasible and reliable.Based on linear elastic hypothesis and finite element method, the dynamic whole displacement state and load of the bridge can be obtained through surveying partial displacements. On this basis, we can further calculate the internal forces of the entire bridge structure, and draw the real-time internal force figure of a bridge The causes of indefiniteness are analyzed in terms of the structure materials, the geometric parameters of members, and the computation mode of members, and then the related expressions of indefiniteness are presented, together with the statistic parameters from the related findings of the Ministry of Communications projects. We can modify the structure resistance of the bridge through the resistance statistic parameters. At the bridge operating process,the《Specification for Inspection and Evaluation of Load-bearing Capacity of Highway Bridge》can be used to modify the structure resistance of the bridge. Finally, the theory of internal force's envelope in the bridge tele-monitoring appraisal system is applied in Gaojia Huayuan Jailing River Bridge.