ANALYSIS OF DEEP EXCAVATION WITH COLUMN TYPE OF GROUND IMPROVEMENT INSOFT CLAY

To minimize the ground settlement induced by the excavation, the colum n type of ground improvement has been used in many parts of the world, possibly due to the fact that this type of soil improvement is relati vely easily produced and conceptually understood. However, an analysis method and design concept has not yet been established at this time. In this paper, a method for evaluating composite material properties o f the treated soil mass is proposed, in which the treated soil area is replaced by a single material during analysis. This allows a three-di mensional analysis to be performed with less computer storage and comp utation time. Furthermore, a slight modification was made on the metho d, which makes plane strain analysis also applicable to the column typ e of soil improvement. The analysis method was supported through a mod el test and a case history.