A Novel Distributed Fiber-Optic Hydrostatic Pressure Sensor for Dike Safety Monitoring

Pore water pressure is the main driving force for soil collapse in nature. River dikes, earth dams, and the foundation of structures built in water are eroded by internal infiltration into the soil (seepage/piping) or flow (scouring/overtopping). Climate change and the spread of urbanization increase the fragility of areas prone to flooding. Current methodologies for early detection of ongoing damage caused by water to these structures are inadequate for preventing structural collapse. Traditional hydrogeological monitoring is based on visual inspection of the infrastructure. In this research, a novel distributed fiber-optic pressure sensor (DPS) was developed to measure variations in the pore water pressure with a spatial resolution of decimeters and over lengths in the order of kilometers. Extensive controlled pressure and temperature variation tests were carried out for calibrating the water pressure and temperature sensitivity of the DPS. The resulting design of the sensor achieved a high sensitivity of 0.1 kPa (1 cmH2O). Additionally, the DPS functionality was validated in a reduced-scale test embankment.