Seismic and Structural Behaviour of Oil Storage Tank of Large Capacity

This research has focused on the behavior, under seismic conditions, of already existing steel storage tanks of large capacity, located in high risk zones. From the revision of analysis and design criteria concerned with thin walls structures, it has been prepared a procedure based on a numeric modeling where the mechanic characteristics of the materials and the real geometrical measures have been considered. Numeric analysis by FEM have been used in different conditions: empty tanks vibration, full tanks where fluid-structure interaction is considered to the case of flexible walls, in order to take into account the pressure distribution of the liquid. To estimate the response, real seismic records originated in the Mexican Region, have been used. Finally the numerical results obtained of the empty tanks with those calculated analytically are compared and it is observed that a good correlation between both approaches. For the results obtained of the fluid-structure interaction models with the selected seismic registry is observed that given its great dimensions and the rigidity that provides the ring to them in the top part of the tanks, the effect of the surge is not very significant due to the fluid system — structure is excited in the first seconds, reason why the action of the hydrostatic pressure on the walls of these is sample to be dominant.