ABSTRACT

In nature, many landslides exhibit a ‘start-stop’ nature. Exploration of this behaviour is difficult in a constant rate of strain test, and it requires a constant shear stress device in which the normal effective stress can be varied on a sample already at residual strength. The paper briefly describes the Authors’ ring shear device, and presents the results of tests carried out on clay samples. The paper explains how this apparatus and procedure better simulate the in-situ conditions of start-stop landslides. The Authors use a traditional (Bromhead) ring shear apparatus modified to allow the necessary stress conditions to be used. The results confirm that the clayey soils show the shear strength regain phenomenon described elsewhere, and the recent tests improve understanding of this behaviour. The innovation in the present work is related to understanding and analysis of the evolution of the different phases of the ‘creep’ on landslide sliding surfaces.