Study On Health Monitoring Of T-Frame Bridge In Service

The safe operation of large-scale bridge has become the serious issue which influenced the national economy and livelihood of the masses. Under the building of long-term health monitoring and condition assessment system of large-scale bridge, bridge management department is able to obtain the bridge service condition real-timely and make maintenance strategy in time, which helps improve detection efficiency and save the expense of maintenance in a great extent. Therefore, establishment of long-term health monitoring and condition assessment system of large-scale bridge appeared high economic benefit and social benefit.This thesis takes the T-Frame Bridge in service-324 State Road Wulong River Bridge as the project background. A long-term health monitoring and condition assessment system of T-Frame Bridge in service has been established with referencing constructed bridge monitoring systems. The main research works and conclusions are as follows:(1) A three dimensional FE model of Wulong River Bridge is constructed and the theoretical analysis of static and dynamic is performed by using ANSYS. Based on the identified data through the loading test, a refined FE model, which can be a reliable benchmark model for long-term health monitoring and condition assessment system of this bridge, is obtained by updating the initial FE model. Moreover, with the updated FE model, Threshold Value of the bridge deflection and stress are acquired under the most adverse live load. Deformation forewarning model and stress forewarning model of Wulong River Bridge are established.(2) Referenced current domestic and foreign bridge health monitoring as well as the appraisal theory, a multi-level hierarchical relational model that reflects bridge service condition in a more scientific and comprehensive way is generated. Furthermore, based on the uncertain analytic hierarchy process with the group decision-making, set-value statistics, barycenter decision theory and variable weight principle, the comprehensive state assessment system of Wulong River Bridge is established.(3)The first floor indicator weights computational method is studied, and the strength reserve comparison method which has been separated from artificial subjective factor is introduced to judge measuring points weights of stress and deflection.(4) Health monitoring and condition assessment system of T-Frame bridge in service is built. With the system, real-time monitoring and assessment online is able to realize, which provides the basis for bridge management department to make decision. Eventually, the comprehensive assessment system software of T-Frame Bridge in service is initially developed by using Visual C++ language. A mass of real-time monitoring datas can be analyzed automatically and bridge security condition can be obtained in time with the help of this software.