Dynamic Centrifuge Model Test Focused on Settlement of the Residence Improved with Grid-form deep mixing walls

Abstract

Liquefaction owing to the 2011 earthquake off the Pacific coast of Tohoku caused heavy damages to private houses in the reclaimed land at the Tokyo Bay area and Tone River basin. A project to prevent liquefaction at housing sites and roads was planned for this area, and the city of Urayasu adopted the grid-form ground improvement technique. A study focusing on the settlement of houses was conducted using under-ground modeling parameters considered by the “Urayasu Feasibility Study Committee for Measures Against Liquefaction” and the dynamic centrifuge model tests of sand mounds eruption. The study investigated the effect of grid-form ground improvement in controlling liquefaction in the event of a magnitude 9.0 earthquake with ground surface acceleration of 200 -gal. The results suggest that the grid-form ground improvement minimizes the settlement of houses by decreasing grid intervals whereas increases in pore water pressure directly under the houses increase the settlement.