Effect of wetting on pore structure of compacted fine-grained soils

Gowthaman Sinnathamby, Debra H. Philllips, V. Sivakumar, Andras Paksy

In the proceedings of: GEO2011: 64th Canadian Geotechnical Conference, 14th Pan-American Conference on Soil Mechanics and Geotechnical Engineering, 5th Pan-American Conference on Teaching and Learning of Geotechnical Engineering

Session: Behaviour of Unsaturated Soils

ABSTRACT: Pore structure of fine-grained soils can be affected by wetting and drying cycles. The flow of water in vertical and lateral directions occurs through the pores in these soils. However, redistribution of these pores due to wetting and drying could affect the hydraulic conductivity of fine-grained soils. The purpose of this study is to investigate the change in soil structure before and after the wetting at the microscopic level. Compacted samples prepared from two natural clay-rich deposits which are widely used as landfill liner material were subjected to wetting. Specimens were taken from these samples before and after wetting for Scanning Electron Microscope (SEM) observations. It was found that wetting influenced the pore structure of both fine-grained soils and this may be attributed to the change in hydraulic conductivity of the landfill barrier layers. Keywords: Pore structure, Hydraulic conductivity, SEM analysis, Landfill liners

RESUMEN: La estructura porosa de los suelos de grano fino puede verse afectada por ciclos de humedecimiento y secado. El flujo de agua en dirección vertical y lateral se produce a través de los poros en estos suelos. Sin embargo, la redistribución de estos poros, debido al humedecimiento y secado, podría afectar a la conductividad hidráulica de los suelos de grano fino. El propósito de este estudio es investigar el cambio en la estructura del suelo antes y después del humedecimiento a nivel microscópico. Muestras compactadas preparadas a partir de dos depósitos naturales ricos en arcilla, ampliamente utilizada como material de revestimiento de vertederos, fueron sometidas a humedecimiento. Las muestras fueron tomadas antes y después del humedecimiento para las observaciones del Microscopio Electrónico de Barrido (MEB). Se determinó que el humedecimiento influyó en la estructura porosa de ambos suelos de grano fino, y que esto se podría atribuir al cambio en la conductividad hidráulica de los revestimientos del vertedero. Palabras clave: Estructura porosa, Conductividad hidráulica, Análisis MEB, revestimientos vertedero

Access this article:
Canadian Geotechnical Society members can access to this article, along with all other Canadian Geotechnical Conference proceedings, in the Member Area. Conference proceedings are also available in many libraries.

Cite this article:
Gowthaman Sinnathamby; Debra H. Philllips; V. Sivakumar; Andras Paksy (2011) Effect of wetting on pore structure of compacted fine-grained soils in GEO2011. Ottawa, Ontario: Canadian Geotechnical Society.

@article{GEO11Paper1078,author = Gowthaman Sinnathamby; Debra H. Philllips; V. Sivakumar; Andras Paksy ,title = Effect of wetting on pore structure of compacted fine-grained soils,year = 2011}