The Suitability of the Osmotic Technique for the Long-term Testing of Partly Saturated Soils
Monroy, R
Imperial College London, London, SW7 2AZ, United Kingdom

Ridley, A
Geotechnical Observations Limited, Brunel University Science Centre, Egham, Surrey, TW20 0JZ, United Kingdom

Dineen, K
Thomas Telford Limited, Thomas Telford Training, 1 Heron Quay, London, E14 4JD, United Kingdom

Zdravkovic, L
Imperial College London, London, SW7 2AZ, United Kingdom

(Received 19 July 2006; accepted 13 September 2006)

Abstract

The understanding of partly saturated soil behavior can be enhanced with the help of additional specialist testing in the laboratory. From the various techniques available to do so at present, the osmotic technique is probably the simplest one. However, there are concerns with the response of this system over time, and in particular its ability to sustain suctions for long periods of time. In this study, the response of a synthetic semi-permeable membrane in conjunction with a solution of high molecular weight has been investigated. The behavior of the osmotic system has been studied both in isolation and in full scale tests, by incorporating it into a purposely built oedometer. Not only was it possible to establish a calibration curve of osmotic potential versus concentration of solution but, additionally, it was possible to perform tests which extended for up to five months. The results suggest that with the correct choice of semi-permeable membrane and solution, it should be possible to use the osmotic technique in a satisfactory manner to perform any desired test on partly saturated soils, regardless of its duration.

ASTM International is a member of CrossRef.
Author Monroy R, Ridley A, Dineen K, Zdravkovic L Title The Suitability of the Osmotic Technique for the Long-term Testing of Partly Saturated Soils Symposium , Committee on