Seismic Damage Detection in Reinforced Concrete Piers of Kordestan- Mullasadra Bridges (Numerical Study) Using RID Functions and Tensor Method

The purpose of this study is to identify the most vulnerable pier in a real bridge sample using the tensor method. Therefore, after modeling the Kordestan-Mullasadra Bridge as one of the most vital arteries of the transportation system in Tehran in OpenSees software, the signals recorded by displacement sensor at the control points of the bridge, before and after the earthquake event were subjected to the action of a sine wave load of 5π angular frequency, using RID functions in Matlab software were processed. Then, the 2d matrix of time-frequency and 3d plan of time-amplitude-frequency have been studied for all piers of the bridge. By calculating the difference of the time-frequency matrix before and after damage and normalizing the responses, the most vulnerable pier is identified. In order to ensure the accuracy of the output results, by creating the damage pattern at the pier1 of FHW04 bridge, the damaged pier is detected by acceptive accuracy according to the method used in this study. The results of this study indicate that the most vulnerable pier of Kordestan-Mullasadra Bridge is based on signals recorded by the displacement sensor, the pier number 8 with the failure index 1. Respectively the pier number 7 with the 0.548 failure index, the pier number 2 with the 0.433 failure index and the pier number 6 with the 0.255 failure index are ranked next to the most vulnerable middle pier of Kordestan-Mullasadra street bridge.