Experimental study conducted on a liquid-filled combined conical tank model

Elevated water tanks are often built with a superstructure vessel consisting of a truncated cone with a top superimposed cylindrical cap. Such vessels are referred to as 'combined conical tanks'. This study is motivated by the lack of procedures for the seismic analysis and design of such structures. It reports the first experimental study conducted on a small-scale combined liquid-filled conical shell model. Shake table testing is conducted to determine the fundamental frequencies as well as the frequencies of vibration of the modes during which the cross section of the tank remains circular (cos(θ)-modes). The later are responsible for the base shear force and overturning moment acting on the tank. Results of the experiments are used to validate the assumptions employed in a previously developed analytical model for the free surface sloshing motion and a numerical model for the vibration of the liquid-shell system. In general, excellent agreements are shown between the analytical and the experimental results as well as between the numerical and the experimental findings.