Permanent monitoring of "Infante D. Henrique" bridge based on FDD and SSI-COV methods

Abstract

A multi-channel dynamic monitoring system was recently installed in a long span concrete arch bridge to continuously evaluate the variation of its dynamic modal parameters, with the final goal of demonstrate the feasibility of application of damage detection methodologies based on modal parameters shifts. This paper characterizes the bridge and the monitoring system used and presents the results achieved, for a period of 6 months, with a software developed in Matlab environment, to process the data that is received at the Faculty of Engineering of the University of Porto (FEUP) through an internet connection. The implemented routines perform on-line automatic identification of the bridge modal parameters using two different approaches: the Frequency Domain Decomposition method and the Covariance driven Stochastic Subspace Identification (SSI-COV). In the latter case, a new algorithm for automatic identification based on clustering techniques is presented.