Theoretical and experimental free vibrations of tall industrial chimney with flexibility of soil

In the first part of this paper natural vibration frequencies and natural modes of the 250 m high-multi-flue-industrial chimney, located in the power station of Opole, with flexibility of soil have been evaluated through the application of the finite element method. In the second part full scale experimental investigations of the free vibration response have been carried out applying two geophone sensors. The analytical and experimental results have been compared. The conclusions concerning the influence of the soil flexibility under the foundation of the chimney on the results of free vibrations have been drawn.