When earthquake occurres, acceleration and horizontal displacement of structures are getting increased as the increment of structures' height. Liquid storage tank can be effected by the fluid-structure interaction in addition to its own dynamic behavior of structures. For the reduction of earthquake damage to the structure, base isolation system is recently and commonly used method.
In this thesis, a study on the base isolation effects for the liquid storage tank was carried out. The proposed model considered the horizontal deformation of the ground as well as the fluid-structure interaction. This study performed to define a relation of dynamic behavior of structures between three items ; inner condition of tank(empty or full), type of base isolator(LRB or SRB) and variation of periods of base isolator.
It was found that long period(soft) base isolation system was more efficient for the reduction of base shear which is the major cause of the damages to the liquid storage tank. SRB type was more efficient than LRB type when short period of base isolator was used. But the efficiency was decreased as the peiord of base isolator was increased, and there was no difference between LRB and SRB type when the long period of base isolator was used. When the long period of the base isolator was installed, the drift between top and bottom of the tank was controlled not more helpfully than the case that short period base isolator was used.