Influence of geotextile encasement on the behaviour of stone columns: Laboratory study

Miranda, Marina; Da Costa, Almudena; Castro, Jorge; Sagaseta, C�sar

Abstract

This paper presents a study of the influence of the geotextile encasement on the behaviour of soft soils improved with fully penetrating encased columns. This influence is analysed by means of measuring soil-column stress distribution, pore pressures and soil deformation during the consolidation process. For this purpose, a horizontal slice of a representative “unit cell” has been analysed by means of small-scale laboratory tests. The tests were carried out in a large instrumented Rowe-Barden oedometric cell. Results showed that the vertical stress supported by encased columns is about 1.7 times that sustained by the non-encased ones. The stress concentration factor for encased columns is between 11 and 25, which is clearly higher than that obtained in tests with non-encased columns, which are between 3 and 6. Finally, the improvement in relation to settlements is presented by the ratio of settlement in soils reinforced with ordinary or encased columns and the settlement of non-treated soft soil. This settlement reduction factor is around 0.6 when the soil is treated with encased columns and 0.8 for soil with non-encased columns.

Citation

Miranda, M., Da Costa, A., Castro, J., & Sagaseta, C. (2017). Influence of geotextile encasement on the behaviour of stone columns: Laboratory study. Geotextiles and Geomembranes, 45(1), 14-22. https://doi.org/10.1016/j.geotexmem.2016.08.004

• Journal Article Type: Article
• Acceptance Date: Aug 29, 2016
• Online Publication Date: Sep 22, 2016
• Publication Date: 2017-02
• Deposit Date: Nov 23, 2016
• Publicly Available Date: Sep 23, 2017
• Journal: Geotextiles and Geomembranes
• Print ISSN: 0266-1144
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 45
• Issue: 1
• Pages: 14-22
• DOI: https://doi.org/10.1016/j.geotexmem.2016.08.004
• Keywords: Geosynthetics; Small-scale test; Soft soil; Settlement reduction; Stress concentration factor; Encased-columns
• Public URL: http://researchrepository.napier.ac.uk/Output/436309