In situ measurement of rockfill dam settlement using fiber optic gyroscope monitoring system

Abstract

Summary The internal settlement of the dam body is an important index for evaluating its operation status. In this paper, using the fiber‐optic gyroscope (FOG), an advanced monitoring system for continuously measuring the internal settlement of the rockfill dam was developed, which mainly consists of a pipeline, an intelligent vehicle, and a power unit. The pipeline was composed of seamless steel pipes and polyvinyl chloride polymer connectors, which was buried at a specific elevation of a section of the rockfill dam body to serve as a permanent settlement monitoring channel. The intelligent vehicle was equipped with a high‐precision FOG sensor and an SD card. During the monitoring, a low‐pass filter was employed to eliminate the vibration noise from the angular velocities of the sensing vehicle as it passed through the connectors. The principle of the monitoring system measuring settlement was derived in detail. Finally, this system was applied to measure the in situ internal settlement of the Houziyan rockfill dam at the beginning and 3 years after the operation to verify its feasibility and accuracy.