Safety Evaluation And Healthy Monitering Of Continuous Beam Bridge

With the increase of traffic volume, damage occurred in many bridge, which may resulting bridge damage and accident. Thus, it is important to detect and evaluate the safty of old bridge. For a bridge in service for decades, kinds of damage were unavoidable, which need repare, reinforce and transform. Before bridge reinforement, dectect and evaluation are needed for bridge to obtain actual capactiy, damage and its casue, thus obtaining effective reinforce measures.Based on the fruit of existed bridge safety evaluation result and extablished heathy mointoring system, this paper makes an introduction of generally algorithm for bridge safety evaluation, including Analytic Hierarchy Process, fuzzy comprehensive evaluation method, artificial neural network method and Dutlephy expert evaluation method. The meaning, process and characters are explained for each method. The structure healthy mointoring system is character with composive considering structure mointoring, system identification and structure evaluation. At present, what is generally approve is test mode analysis method which consider the system identification, vibration measure teccnology, signial collection and so on. Various structure dectection methods are analysed including comparasive analysis method, artificial neural network method, expert system method, mode identification method, and fuzzy math method. The structure damage mointoring technology is divided into local and golobal mointoring according to mointoring purpose.Based on the knowledge above, in the established system of safty evaluation and healty mointoring for continuous bridge, the safety evaluation index for super structure, pier and foundation respectively. The bearing part in super structure of bridge, pier, foudation and support. All of these parts affect the bearing behavior and service life of bridge.A three span continous prestressed concrete box girder birdge was selected for case study. Using strain gage and static level, it was measured the strain, deformation, and crack. Based on mointoring result and method, the healthy mointoring system were extablished based on Visual Studio 2010.