ABSTRACT
With increasing fines content in the grain size distribution of sands, the spacing between compaction probes needs to be decreased to obtain sufficient compaction when using the vibro compaction technique. Vibro stone columns are in general used to improve characteristics such as the strength and compressibility of fine-grained cohesive soils that are deemed insufficient for the geotechnical purpose. These soils are predominantly water-bearing silty and clayey sands, sandy silts, and silt and clay mixtures. This chapter discusses certain definitions and some of the terminology used in conjunction with ground improvement by vibro replacement stone columns. For the construction of vibro replacement stone columns employing the wet method, essentially the same equipment is needed as for the vibro compaction process. The special bottom feed equipment both for crane-hung and vibrocat operation is today the standard setup for dry stone column construction.
