Application of fiber optic sensors at different tunnel linings at the Kühtai 2 hydropower station

Abstract This study presents the innovative application of fiber optic sensors, specifically Fiber Bragg Grating (FBG) sensors, in the Kühtai 2 hydropower station project in Austria. The project involves the construction of a pressure tunnel connecting the Kühtai and Finstertal reservoirs, incorporating concrete linings with and without sealing membrane as well as steel linings. The sensors were accurately installed individually to each lining type, overcoming problem statements such as positioning sensors on unreinforced concrete without damaging the sealing foil or compromising the structural integrity. The monitoring system enables real‐time data collection on strain and temperature variations during key phases, including concreting, prestressing, pressure, or filling tests. This approach illustrates the effectiveness of integrating fiber optic technology into hydropower infrastructure, offering enhanced monitoring accuracy and improved decision‐making for maintenance and operational strategies. The findings serve as a reference for future projects, presenting the potential of the demonstrated sensor applications in demanding engineering environments.