Stabilization of soil with displacement columns of dry sand-cement/lime mix: construction methods, physical behavior and numerical modeling

摘要

In recent years small diameter displacement-columns to improve the bearing capacity of soft soil and to reduce settlements have been developed. The method is called Combined Soil Stabilization with Vertical Columns or CSV. A dry mixture of sand, cement with or without unslaked lime is forced into the soil by a continuous flight auger. Through capillary action ground- or por e-water penetrates the granulate column and allows it to harden. The paper describes the CSV Soil Stabilization System in detail: equipment, stabilization material, process, quality assurance and quality control procedures. A newly developed numerical model and design concept for the complex interaction between CSV columns and soil is presented. The results of the numerical analysis are compared to results of large scale field tests with extensive monitoring.