Seismic and Structural Health Monitoring of Dams in Portugal

Abstract

This chapter is focused on the Portuguese experience on the development and exploration of systems for continuously monitoring dam vibrations, using accelerometers. The pioneer system for seismic and structural health monitoring (SSHM) installed in Cabril dam (the highest Portuguese arch dam: 132 m high) is described in detail. The design of this system was the result of a long-term LNEC research program, still ongoing. These monitoring systems should include software developed to automatically perform the analysis of collected data, including the automatic comparison with numerical results from 3DFE models. In view of the good results obtained with the system in operation in Cabril dam since 2008, similar systems have been installed in other large dams in Portugal, particularly in recently built dams. Finally, Baixo Sabor dam is presented as an example of a new Portuguese dam with a complete SSHM system, in operation since 2015. The main experimental results obtained for both dams are shown, namely the evolution of natural frequencies over time, mode shapes and the measured seismic response to earthquake events.