Seismically induced loads on internal components submerged in waste storage tanks.

摘要

As new equipment is designed and analyzed to be installed in the double-shell waste storage tanks at the Hanford Site near Richland, Washington, the equipment and the tank integrity must be evaluated. These evaluations must consider the seismically induced loads, combined with other loadings. This paper addresses the hydrodynamic behavior and response of structural components submerged in the fluid waste. The hydrodynamic effects induced by the horizontal component of ground shaking is expressed as the sum of the impulsive and convective (sloshing) components. The impulsive component represents the effects of the fluid that may be considered to move in synchronism with the tank wall as a rigidly attached mass. The convective component represents the action of the fluid near the surface that experiences sloshing or rocking motion. The added-mass concept deals with the vibration of the structural component in a viscous fluid. The presence of the fluid gives rise to a fluid reaction force that can be interpreted as an added-mass effect and a damping contribution to the dynamic response of the submerged components. The distribution of the hydrodynamic forces on the internal components is not linear. To obtain the reactions and the stresses at the critical points, the force distribution is integrated along the length of the equipment submerged in the fluid.