EFFECTS OF VERTICAL INCIDENT WAVE ON LIQUEFIABLE GROUND RESPONSE

Abstract

Coupling effect between horizontal and vertical behavior is investigated through the three-dimensional effective stress earthquake response analysis. The interactive effect is hardly observed in the saturated homogeneous model ground under the sinusoidal input motion in both horizontal and vertical directions. The coupling effect appears, however, in the unsaturated ground; effective confining stress changes under vertical motion, and vertical motion appears under the horizontal vibration because of dulatancy effect. Finally, the Port Island vertical array record obtained during the 1995 Hyogo-ken Nanbu earthquake is simulated, and the behavior observed in the preceding analysis is confirmed to occur.