Environmental and operational effects on modal properties of dams: Foz Tua Arch Dam

Abstract

Vibration-based structural health monitoring systems relying on the identification and tracking of modal properties have become more and more common during the past few decades and, nowadays, successful implementations can be found in structures as different from each other as bridges, towers, wind turbines and concrete dams. These systems are used to study the evolution of the structure dynamic properties over time and to look for the occurrence of novel structural behaviour, which may indicate the presence of damage. Nevertheless, civil engineering structures are subjected to environmental and operational conditions, such as temperature, wind or traffic intensity, whose variations affect the dynamic response of the structure. Therefore, only through the minimization of the effects due to the mentioned conditions on structures modal properties it is possible to analyse the real evolution of the structure dynamic behaviour. In this context, this paper introduces the continuous dynamic monitoring of Foz Tua arch dam, in Portugal. The monitoring system installed in the dam is addressed and the results obtained during two years of continuous monitoring are presented. Finally, multiple linear regression models (MLR) and principal components analysis (PCA) are used to minimize the effects of environmental and operational conditions on modal properties. (c) 2021 International Conference on Structural Health Monitoring of Intelligent Infrastructure: Transferring Research into Practice, SHMII. All rights reserved.