PSI - Issue 81

Mykhailo Hud et al. / Procedia Structural Integrity 81 (2026) 434–438

438

4. Conclusions This study examines the dynamic behavior of a reinforced concrete pool bowl under the influence of hydrostatic pressure and water mass, using numerical simulations. The analysis also revealed the main trends in how natural frequencies change depending on the pool’s filling level. The results show that water increases the structure’s stiffness, as reflected in the h igher frequency spectra for both fully and partially filled conditions. Interestingly, the frequencies for these two states are nearly identical, suggesting that even a half-filled pool provides enough internal stabilization thanks to the pressure and inertia of the water. By contrast, an empty pool shows a noticeable drop in frequency range. Without the support from the water, the structure’s own flexibility dominates. These lower frequencies make the pool more susceptible to operational or seismic loads, which could lead to resonance. Comparing the three frequency spectra makes it clear that the pool is much stiffer when filled, while the empty bowl behaves considerably more flexibly. These findings highlight the importance of considering the actual water level when assessing the dynamic stability of reservoir structures or during the design process. References Hashemi, S., Mousavi, S., Kianoush, M.R, 2013. Dynamic behavior of flexible rectangular fluid containers. Engineering Structures 46, 671–684 https://doi.org/10.1016/j.tws.2013.02.001 Housner, G.W., 1963. The dynamic behavior of water tanks. Bulletin of the Seismological Society of America 53, 381–387 https://doi.org/10.1785/BSSA0530020381 Hud, M.,2024. Analysis of the influence of horizontal ties on the buckling of the bottom of a floating pool. Procedia Structural Integrity 59, 617–621 https://doi.org/10.1016/j.prostr.2024.04.087 Kianoush, M.R., Ghaemmaghami, A.R., 2011. The effect of earthquake frequency content on the seismic behavior of concrete rectangular liquid tanks. Engineering Structures 33(7),2186–2200 https://doi.org/10.1016/j.engstruct.2011.03.009 Myung, J.J., Kang, S.S.,2019. Fluid effect on the modal characteristics of a square tank. Nuclear Engineering and Technology 51(4), 1117–1131 https://doi.org/10.1016/j.net.2019.01.012 Veletsos,A.S., Yang, J.Y.,1977. Earthquake response of liquid storage tanks, advances in civil engineering through engineering mechanics.ASCE, 1–24 Virella, J.C., Godoy, L.A., Suárez, L.E.,2008. Linear and nonlinear 2D finite element analysis of sloshing modes. Journal of Sound and Vibration 312 (1–2), 278– 300 https://doi.org/10.1016/j.jsv.2007.07.088