Lateral swelling pressure developed in an active clay

Abstract

A laboratory technique for the determination of the lateral swelling pressure developed in a high plasticity clay during the ingress of water is described. The technique used was the “Method of swell under load”, and the equipment used was a hydraulic triaxial cell together with a radial strain belt. Comparison with results of similar tests using a conventional oedometer showed the lateral swelling pressure to be approximately twice the vertical equivalent. The lateral swelling pressure determined from this technique was shown to be sensitive to the original moisture content of the clay, as would be expected. It is suggested that this method enables the estimation of swelling pressures generated during known, finite displacements. Disadvantages of the method are the length of time required to conduct sufficient tests to accurately compute the swelling pressure, and the need to prepare a number of similar samples.