The dynamic behavior of water tanks

During the Chilean earthquakes of May, 1960, a number of large elevated water tanks were severely damaged whereas others survived without damage. An analysis of the dynamic behavior of such tanks must take into account the motion of the water relative to the tank as well as the motion of the tank relative to the ground. Some simple expressions are given for the pertinent dynamic properties of tanks with free water surface. A simplified dynamic analysis is indicated for the response of elevated water tanks to earthquake ground motion.