This paper presents a case study focused on the Brajdica railway tunnel, which carries the Zagreb-Rijeka railway line into the port of Rijeka in Croatia and thus represents a critical node on the European TEN-T network. The tunnel is undergoing a major reconstruction project to increase its capacity. As part of this work an extensive embedded monitoring system comprising inclinometers, extensometers, micrometers and survey markers were installed to monitor the tunnel response. This data is supplemented with periodical laser scanning of the tunnel interior. Measurement profiles are set along the tunnel bore and the data collected is used for the development of a tunnel performance model. Long-term monitoring data from a neighbouring road tunnel was used to develop models tho predict the long-term response of the Karst bedrock in the area. Combining these models with the settlements measured during the construction phase of the works at Brajdica railway tunnel allow prediction of settlements and the future occurrence of damage in the rail tunnel. Based on different limit states, life cycle management scenarios are developed and used for maintenance planning, with the aim to decrease short and long-term risks. This work has been performed within European H2020 SAFE-10-T project.

tunnel, monitoring system, life cycle cost model, maintenance plannign