| Abstract: |
Liquid-retaining structures are lifeline facilities whose damage or collapse during an earthquake can interrupt drinking-water supply and hamper post-disaster relief. This study performs an empirical, parametric assessment of the seismic response of a ground-supported rectangular reinforced concrete water tank using the finite-element program STAAD.Pro [1]. A rectangular tank was idealised with the Housner two-mass hydrodynamic model, in which the water mass is split into an impulsive component moving with the wall and a convective component coupled through a spring that captures sloshing. Five model configurations were generated to study the influence of water level (empty, half-full, full) and wall thickness (0.25, 0.30, 0.40 m). Response-spectrum analyses were carried out for seismic zones II, III, IV and V of IS 1893 on medium soil with an importance factor of 1.5 and a response-reduction factor of 2.5. The natural time periods, base shear, base moment and top-wall displacements were extracted and tabulated. Results show that the fundamental convective period is substantially longer than the impulsive period, that base shear rises almost linearly with zone factor, and that the full tank attracts approximately 3.3 times the base shear of the empty tank. Increasing wall thickness stiffens the tank and curtails lateral displacement, although the added self-weight partially offsets the stiffness gain. The findings confirm that the full condition and high zones govern design, and that STAAD.Pro with a two-mass idealisation provides a dependable tool for routine seismic evaluation of rectangular RC water tanks [2]. |
