DBPapers
DOI: 10.5593/sgem2017/12/S02.029

DETERMINATION OF THE DENSITY OF STONE COLUMNS USING IN – SITU TESTING

J. Stacho, M. Sulovska
Sunday 10 September 2017 by Libadmin2017

References: 17th International Multidisciplinary Scientific GeoConference SGEM 2017, www.sgem.org, SGEM2017 Conference Proceedings, ISBN 978-619-7105-99-5 / ISSN 1314-2704, 29 June - 5 July, 2017, Vol. 17, Issue 12, 223-230 pp, DOI: 10.5593/sgem2017/12/S02.029

ABSTRACT

A stone column is often used technology of a ground improvement. The design of stone columns is still based on experiences and empirical computational methods. The most important properties of stone column are unit weight of a soil, relative density, strength and deformation properties. The total resistance and deformation of stone column is also significantly affected by properties of the original subsoil. The article deals with determination of the relative density of the stone columns by using the in – situ testing. The tested stone columns were created using a vibro – replacement technology. The stone columns were made of different types of coarse – grained material, e.g. pebble gravel, crushed pebble gravel and quarry stone. A dynamic penetration test and a pit test were used for determination of the relative density over the column’s length (depth). The tested stone columns were installed into fine – grained subsoil as well as into coarse – grained subsoil. The type of coarse – grained material has significant impact to the density index in a depth more than 0.5 m below the surface. The results of study show, that the density index of the stone column, regardless coarse – grained material, responsible to medium dense and dense relative density, only in few cases to very dense relative density.

Keywords: stone columns, ground improvement, unit weight of soil, density index