Centrifuge Model Test Study On The Deformation And Stability Of Expansive Soil Slope

In this paper, the engineering properties and study progress of expansive soil are introduced at first, and a series of geotechnical centrifuge model tests were carried out to study the influence of water content, dry density, slope gradient, overpass of water and circulations of drying and wetting on the deformation and stability of expansive soil slope. Conclusions were drawn as fellows:Expansive soil slopes with low water content, high dry density and gentle gradient will be more stable, and water content seems to be much more important. Failure with deep round sliding face can also happen when the slope soil has high water content and low dry density. In fact, most expansive soil slopes are very stable originally, and the action of a certain water level in a short time will not influence the stability of the slope very much, but their stability will reduce with the influence of circulations of drying and wetting. The main reason of this is that cracks will take place during the drying process of expansive soil and water can infiltrate into the deeper part of the slope during the wetting process. Cracks will widen and deepen and water will influence more part of the slope with the increase of circulation and this will lead to the decrease of strength and the increase of the deformation, eventually result in the failure of the slope. The first two circulations will greatly reduce the stability of the slope, and water is the most important factor for the stability of the slope. In order to prevent the failure of expansive soil slope, much attention should be paid to the waterproof and drainage of the toe of the slope because failure often starts from this part of the slope. Geotechnical centrifuge model test technical has a lot of advantages compared to prototype observation, indoors test and theoretic analysis, and it is a effective means to study the deformation and stability of expansive soil slope.