Vibration-Based Scour-Detection for Bridge-Piers Using a Self-Powered Magnetostrictive Vibration Sensor

Considering the drawbacks of existing scour detection systems, such as expense for installation and sensitivity to pier damage, this letter developed a vibration-based scour detection sensor that can be installed without the construction of power lines. Our final objective is the realization of a system that can generate electric power from bridge vibrations caused by passing trains, temporarily store the generated energy, use that energy to measure the natural frequency of a bridge pier, and transmit the measurement results to a server via wireless communication. As the first step in the system development, we conducted field tests to confirm whether the developed sensor could measure the natural frequencies of bridge piers. The time-series data of the sensor output were obtained and transmitted using a wireless transmission module, which was made as a part of the development of the system. The experimental results confirmed that the natural frequencies of the bridge pier could be measured even from the output voltage caused by the microtremors of the pier. Thus, the developed vibration sensor can be used to conduct long-term monitoring of the scour conditions of bridge piers.