Characteristics of Geotechnical Behavior of the Deep Cement Mixing Method According to the Placement Type

Abstract

The improvement method for using the soft ground efficiently was applied in various manners depending on the site condition and development purpose. Recently, there has been an increasing interest in the deep cement mixing (DCM) method, in which the lower part of the ground is mixed with a solidifying agent to form an improved body of uniform strength. Although various studies are being conducted on this topic, studies on the behavioral characteristics of the improved ground according to the arrangement of the DCM improved body are insufficient. Therefore, in this study, an improved body was manufactured using a model soil with a similar ratio, and laboratory tests were conducted to understand the behavioral characteristics of the composite ground in pile-type and wall-type arrangements. The replacement rate of the composite ground was set at 46.2%. The improved body was manufactured at W/C = 40%. A shear test was performed after installing displacement gauges at 8 cm and 16 cm from the center of the load plate to clarify the ground behavior. The test results suggested that the wall type arrangement was advantageous in the force for the load acting vertically and the displacement for the lateral flow. Additionally, numerical analysis using the finite element method suggested that significant ground displacement occurred in the pile-type arrangement.