ANALYTICAL STUDY BY STRAIN SPACE MULTIPLE MECHANISM MODEL ON DEFORMATION OF IMPROVEMENT GROUND USING ARTIFICIAL DRAIN MATERIAL DURING EARTHQUAKE

Abstract

 In excess pore water pressure dissipation method as a countermeasure against liquefaction, it is pointed out that there is no “tenaciousness” because the effects to reduce excess pore water pressure ratio are lost if level of earthquake intensity exceeds expected scenario. However, the disaster mitigation effects of earth structures such as quay walls using artificial drain material were observed during large scale earthquake such as the 2011 off the Pacific Coast of Tohoku Earthquake. In this study, in order to reveal “tenaciousness” of the effects to reduce the deformation of the improvement ground using artificial drain material during earthquake, the effective stress analyses using the strain space multiple mechanism model with permeability were conducted for sloped grounds which are representative earth structures.
 Based on the results of this study, it was found that “tenaciousness” of the effects to reduce the deformation of the improvement ground using artificial drain material remained tough condition even if the earthquake exceeded the scenario, by normalizing residual horizontal displacement of improvement ground with respect to that of unimproved ground and nonliquefiable ground.