The influence of the uplift of building base on an earthquake response is studied by the viewpoint of energy. Dynamic response analyses using both a single-degree-of-freedom system and a frame model with of an eight-story building are executed. The difference of the input energy to a model between the uplift restraint model and the uplift free model is examined. As a result, the following conclusions are obtained. 1) The total input energy of the uplift free model tends to be smaller than that of uplift restrained model. 2) Even if the total input energy of the uplift free model is larger than that of uplift restrained model, the maximum strain energy becomes smaller than that. 3) The energy reduction effect by the basement uplift is also testified by the frame model analysis.
