Static and continuous dynamic monitoring of Foz Tua arch dam

Abstract

Foz Tua dam, located close to Tua river’s mouth, tributary of Douro river (right bank), North of Portugal, is a concrete arch dam 108 m high and 275 m long at crest which was engineered and constructed by EDP – Energias de Portugal S.A.. The first filling of the reservoir took place between June 2016 and June 2017. The dam safety monitoring plan was defined and implemented in accordance with the Portuguese Regulations, considering the construction, reservoir’s first filling and the first exploitation phase. In addition to the conventional devices which compose the observation system, a continuous structural vibration monitoring system, a system to characterize seismic actions at dam site and on the reservoir’s perimeter, as well as to monitor dam response, and a 3D automatic continuous geodetic monitoring system were installed in the dam. A Global Navigation Satellite System antenna to monitor crest displacements was also used during the first filling of the reservoir. Currently, an automatic data acquisition system (ADAS) is being installed, which will incorporate the main data of the above referred systems. So, the aim of this paper is to describe and explain the objectives of these systems which contribute to assure an effective safety control of the Foz Tua dam behaviour.