Overview on the multi-decade database of Portuguese large concrete dams monitoring data

Abstract

Monitoring is a key activity to ensure the structural safety of dams and is used for detection of deterioration, including local degradation issues and more extensive deterioration scenarios, such as the development of internal expansion reactions which, in the worst case scenario, can lead to severe cracking and even to the abandonment of the dam. This paper presents an overview of an information system that includes a monitoring database, which includes the records of the main actions (water level, air and water temperatures and temperature inside the concrete) and of the main structural responses (radial and tangential displacements measured in inverted plumb-lines and using geodetic techniques, displacements measured in rod extensometers and by precision levellings in target points, joint displacements measured in joint meters, bi- and tridimensional strain fields measured in sets of strainmeters). The hydraulic behaviour of the foundation is also monitored, including the measurement of water discharges along the drainage gallery and the water pressure in the foundation (uplift). The database has monitoring data since the construction period of each dam until this date through periodic readings over the years. Different measurements in some dams, with and without identified deterioration processes, are presented and compared in order to showcase the importance of monitoring activities over the structures lifetime.