Rapid Damage Detection Of Bridges Based On Kalman Filter

An approach based on Kalman filter is proposed to diagnose the damage of medium and small span bridges without interrupting the traffic flow. It supports the rapid assessment of carrying capacity of practical bridges.Key issues of the rapid damage diagnosis of bridges and developing trend of damage detection are summarized systematically. The theoretical frame of rapid damage detection of bridges based on Kalman filter is founded by combining Kalman filter theory and damage detection of bridges.This study focuses on basic theories of stationary state Kalman filter and founds out that the effect of load excitation cannot be avoided for damage decision using Kalman filter. Taking advantage of short time interrupting of traffic flow, obtaining the similar load excitation before and after damage of bridges, a damage index is proposed by using the difference of correlation of innovation acquired from Kalman filter. This damage index could alleviate the influence of load excitation on results of damage diagnosis.Utilizing the model test of a bridge, this study analyzes the sensitivity of proposed damage index to structural damage. Some key issues of Kalman filter for detecting damage are discussed, and then the effectiveness of Kalman filter is demonstrated too.Based on above researches, this study verifies the effectiveness of proposed method based on Kalman filter in detecting the damage of a practical bridge by using long term monitoring data. Results show that Kalman filter is a promising method for damage detection without interrupting traffic flow load.