Abstract
The Compaction grouting (CPG) method is one of the liquefaction countermeasures to increase the density of improved ground by injecting mortar statically into the ground. CPG can be often applied just below or near the existing structures, and accordingly ground upheaval often becomes a problem. In this study, regarding Up and Down (U/D) method of a new upheaval control type CPG method, field demonstration experiment was carried out by changing actual construction machines and various parameters.
Consequently, in field verification, the same upheaval control as model tests was obtained by the new U/D method. The proposed U/D method has proven itself in reducing the ground upheaval quantity by more than 90 %. Moreover, by using the concept of the equivalent improvement rate, it is possible to predict the upheaval amount and the density increase of the improved ground by the new U/D method, thereby facilitating a rational design based on the conventional CPG method.
