Abstract
This study showed the two results of effect of the soil improvement using the drain for the preventing liquefaction method. One is a site investigation in the 2011 Tohoku - Pacific Ocean Earthquake, and the other is a shaking table test result using centrifugal model test. At the results of site investigation, the drain improvement ground did not liquefy in the Tokyo port and the Sendai Shiogama port. The model test showed the interesting results. According to the effect of the drain, the excess pore water pressure ratio of the improvement ground became a low value during shaking disturbance. And, the excess pore water pressure became to a low value quickly since the drain effect. Moreover, the density of the improvement ground increased during shaking disturbance since drainage of the drain. The stiffness of the ground was recovered after shaking since the density increased and effective stress recovered.
