Operational modal analysis and seismic assessment of a tall brick chimney

In Western Europe, masonry chimneys were widely used in industrial settings during the 19th century, then gradually abandoned or destroyed from the beginning of the 20th century. Some of these structures are still visible today, but most have been neglected. Interest has developed in the preservation of these chimneys as a cultural heritage. This master thesis presents the seismic evaluation of two masonry chimneys in the surroundings of Porto, Portugal. An in situ investigation is performed using two forms of modal analysis (EMA and OMA) to determine their dynamic structural properties. Then, four different fiber element numerical models are developed and calibrated. The structure is then evaluated by a first analysis with the response spectrum method suggested by Eurocode 8, followed by a non-linear time analysis. The advantages and disadvantages of these two methods are discussed. Finally, the model is compared to the results of a finite element model of shell type.