Monitoring historical industrial chimney by means of operational modal analysis. Case study

Abstract

This paper addresses the study of the structural health of an historical industrial chimney in Spain. The chimney is monitored by means of using operational modal analysis (OMA) and the outcome is compared with the numerical results obtained from a Finite Element model. The OMA is used to determine the dynamic parameters and their effect on the structural behavior. These parameters are related with the health status of the structure and helps in the detection of damages or defects caused by the pass of time and the lack of maintenance. Due to the low frequencies involved capacitive accelerometers have been used for the determination of the natural frequencies. The industrial chimney is located in an old industrial site which has been renovated for modern use. Complementary tests have been used in order to know mechanical parameters of the structure, but especial attention has been paid to modal analysis in this study as a non-destructive approach. The chimney is approximalty forty meters high and is supported by a concrete foundation. No data or documentation has been found about the year of construction but it is supposed to be built at the beginning of the XX century. The results show that there is no significant damage in the structure and the combination of loads to which it is exposed do not supposes a risk for the structural integrity of the chimney.