Distributed Optical Fibre-Based Pore Water Pressure Sensor for Early Warning of Geohazards

Geohazards due to the increase of pore water pressure are adverse geologic conditions capable of causing widespread damage or loss of property and life. To predict the potential consequences of rising water pressure in the subterranean, modest and more accurate methods are necessary. Recent advances in optical fibre sensors enable spatial continuity along with fibre, which is incapable of discrete sensing systems. In this study, the ability of a distributed optical fibre sensor embedded into three silicone rubber membranes in series has been tested for pore water pressure measuring. A backscattered reflectometer has been used to measure the strain variations along the optical fibre. Subsequently, the strain variations along the membranes have been analyzed against the water pressure. It was revealed that the measured strain readings are proportional to the applied hydrostatic pressure. Accordingly, real-time measurements can be obtained frequently from a remote location as the optical fibres can transmit the measured data for long distances.