Operational modal analysis of an end-supported pontoon bridge

A comprehensive monitoring system is installed and currently in operation on the Bergsøysund Bridge, an end-supported floating pontoon bridge, collecting data on accelerations, displacements, waves, and wind. Using covariance-driven stochastic subspace identification (Cov-SSI), data-driven stochastic subspace identification, and frequency domain decomposition, the modal parameters of the structure are estimated to investigate its dynamic behaviour. Aspects regarding the selection of good parameters for the Cov-SSI analyses are highlighted, and the clarifying effect of applying stabilization criteria on multiple orders of output is discussed. The effects of the significant wave height on the modal parameters are investigated based on an automatic selection of stable poles from stabilization plots produced by the Cov-SSI method.