The Preparation of Hollow Cylinder Specimens from Undisturbed Tube Samples of Soft Clay

The use of torsional-hollow cylinder testing apparatus for research into soil stress-strain behavior has grown over the past decade. Most studies have focused on sands or on cohesive materials reconstituted in the laboratory. Studies involving undisturbed soft clay have been neglected, in part due to the difficulties involved in specimen preparation.

The present paper describes a procedure for the preparation of hollow cylinder specimens of very soft undisturbed clay and their mounting in the triaxial chamber. The procedure involves the use of electrosmosis in order to allow “frictionless” cutting of soft saturated cohesive materials. The specimen is supported laterally, axially, radially, and tangentially throughout the entire procedure.

The procedure could easily be adapted for the preparation of specimens of soft clays for any geotechnical laboratory test.