DIRECTIONAL EFFECTS OF EARTHQUAKE-INDUCED SLOSHING IN RECTANGULAR TANKS

The influence of the direction of earthquake motions on the hydrodynam ic loads on a fluid-filled rectangular tank and on the associated ampl itudes of the water surface elevation is investigated. A superposition of the closed-form solution for motion parallel to a pair of sides is used to develop analytical results for an arbitrary direction of moti on. The resulting solution is used to examine the effects of motion di rection on the maximum force on the tank for both harmonic and earthqu ake-induced motions. For a harmonic motion, the highest loads occur fo r a motion parallel to a pair of sides, whereas the highest elevations generally occur for an intermediate direction of motion. For an earth quake-induced motion, both the highest loads and the highest elevation s occur for a motion parallel to a pair of sides. An example applicati on is provided, and the implication of the results on the design of re ctangular tanks is indicated.