An Experimental Study of Insufficient Free Board Effect on Fixed-Roof Cylindrical Tank Seismic Loads

Document Type : Research Article


1 International Institute of Earthquake Engineering and Seismology

2 Babol Noshirvani University of Technology (BUT)


Cylindrical tanks are fundamental structures used for the storage of liquids.
Sloshing caused by earthquakes in tanks without enough freeboard leads to a
liquid impact on the roof of tanks. This study aims to explore the base shear
variation due to insufficient freeboard using experimental and numerical methods.
The experimental tests are performed using a cylindrical liquid tank excited by
various harmonic loads. The impact of some parameters such as the water height to
tank radius ratio and freeboard on base shear force are investigated by conducting
90 tests. Impulsive and convective masses for simplified mass-spring are modified
in numerical models so that experimental and numerical base shear results
are consistent. Finally, a simple analytical solution to estimate the reduction of
convective mass due to insufficient freeboard is suggested and validated using
experimental results.