Earthquake Sloshing in Annular and Cylindrical Tanks

The sloshing response of water in annular as well as in cylindrical tanks under horizontal earthquake ground motions is studied. A linear analysis, developed for the general annular tank problem, is based on potential flow theory. The predicted values of natural frequencies, surface displacements, and dynamic pressures are compared with measured data from shaking table tests. Experimental studies were conducted on 1/80th and 1/15th scale models of a 120-ft (36.6m) annular tank, and correlation data are presented for both sinusoidal and simulated earthquake motions. Test results from the sloshing of water in a 12-ft (3.66m) diam cylindrical tank show that the annular tank solution is also applicable in this case. The range of surface displacement within which linear theory gives satisfactory results was established experimentally.