Research On Condition State Evaluation System And Damage Identification For Prestressed Concrete Girder Bridge

Timely accurate evaluation of bridge technical condition and precise identification of location or degree of occurring damage is the prerequisite of ensuring the function of structure and extending the useful life of bridges.This paper summarizes and compares the existing methods of bridge condition evaluation, and introduces the basic theories and key points of modeling. Then an evaluation index system for load-bearing capacity and durability of existing prestressed concrete girder is established on the analysis of various factors influencing bridge condition. And then the Bridge Condition Evaluation System is developed, including the bridge condition evaluation module, bridge information database and user interface. After that the learning ability, fault tolerance and feasibility of the system are tested and verified through several instances.On the basis of summarizing and analyzing the common methods of structure damage identification, Genetic Algorithms is applied to damage identification of bearings in complex girder bridges. In this paper, the fundamental principles and modeling procedures are introduced, and the objective function, which is the optimization principle of GA, is established with structural modal parameters. The performance of this method is tested and verified through numerical simulation. Results show that noise level is the key factor affecting the accuracy of the method, and some improving suggestions are proposed.