A Study On Reliability Theory Based Safety Evaluation For Bridge Remote Monitoring Systems

The routine bridge load monitoring system plays a very significant role in evaluating the safety performance of a new bridge before its operation or after unexpected damage. However, this kind of inspection unfavorably features discontinuity, interrupting traffic, and repetitious cost on human and material resources. Compared to the routine load monitoring system, bridge tele-monitoring currently and popularly leads the bridge research due to its safety, realtimeness, continuity and intime alarming. At present, researchers have researched on and conducted dynamic finger print method (mode identification method), model modification and system recognition method, neuro-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 sponsorship of the national project—Technology Development of Realtime Safety Tele-Inspection System for Major Bridges (2002BA105C) and after a 3-year research in the related field, attempts to present a bridge tele-inspection appraisal system based on the theory of reliability. The contents and findings of the research are presented as follows.1) Firstly, 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.2) Secondly, the general concept of the appraisal theory of the bridge tele-monitoring system based on the theory of reliability is introduced. The principles and methods of the bridge safety appraisal system are introduced by obtaining bridge load effect statistic parameter through load monitoring data, describing bridge structural resistance through the random variable probability model retrieved from the indirect method, and illustrating the bridge operation conditions through the reliability index β. The analytic results show that the above mentioned system is feasible and reliable.3) On the basis of the hypothetical monitoring theory, the distribution of maximum load effect value and the dynamic fitting technique are presented, and the computerized realization process of the "dynamic analytic system for the load effect statistic parameters of bridge tele-monitoring data" is presented in detail.