Abstract
In order to see the effect of firm boundaries on the characteristic features of the ground motion during earthquake, a series of vibration tests was carried out on a laboratory scale for two typical types of ground formation. The first type of the ground considered was a layer of soft soil resting on inclined underground rigid base. The other type of the ground was a V-shaped inlet-like soil layer, surrounded by vertical firm wall. As results of the model tests, it was clarified how the intensity of vibration is amplified particularly on the ground surface near such typical boundary bases.
