DEFORMATION OF A REINFORCED EARTH DOUBLE STRUCTURE WALL DUE TO AN EARTHQUAKE AND ITS REPAIRWORKS

Abstract

This paper describes a reinforced earth wall deformed after the Iwate-Miyagi Nairiku Earthquake in 2008. Outer wall surface displaced about 170 mm to the front and some of the concrete panels were damaged. The reinforced earth wall is characterized as a double-walled structure. The space between the front concrete panel wall and inner backfill reinforced by geogrid is filled with deformation absorption layer of crushed stones. Because there was no further wall displacement in about 10 months after the earthquake, the reinforced earth wall was considered to be in acceptably stable state. Only the damaged concrete panels were replaced. The backfill reinforced by geogrid was inspected by means of 2-D surface-wave exploration technique and found to be in acceptable conditions corresponding to the Standard Penetration blow counts ranging from 21 to 34.