3-D Finite element implementation of Housner fluid-tank dynamic interaction model in elevated water towers

A 3-D multi-mass finite element model simulating the dynamic fluid-structure interaction in water tanks is presented in this paper. The spatial scheme is derived from the classical Housner analytical model, consisting in a two-mass (impulsive plus convective) representation of the phenomenon, which is being commonly used in most international Seismic Standards and Design Guidelines, and is still a reference also for finite element computation. However, it provides an oversimplified idealization of the interaction effects in time-history seismic analyses, and requires proper adaptations when the tank vessel includes an internal manhole. The 3-D finite element generalization of Housner basic model proposed here allows spreading the hydrodynamic pressure in sloshing conditions on the entire surface of the vessel, as well as correctly transmitting them to the supporting structure, in the case of elevated tanks.