SLOPE GEOMETRY AS A TRIGGERING FACTOR OF FLOWSLIDES

The paper reports a study aimed to the prediction of flowsliding in finite slopes constituted by loose sand. Several authors showed the influence of the in situ state of stress on flowslide occurrence. The dependence of the potential for liquefaction from the pre-failure state of stress requires the determination of the state of stress in the slope. In this study the slope geometry has been investigated as a factor influencing the initial state of stress and hence flowslide occurrence. The initial state of stress of sand slopes characterised by different geometry and different void ratio and groundwater level conditions, is predicted by a finite difference model (FLAC) assum-ing fully drained conditions and linear elastic plastic behaviour of the material. On the basis of the numerical modelling results it is possible to completely define, in any point of the slope, the stress conditions and to analyses the effect of slope height and inclination. By relating this state of stress to the residual strength of the sand at the quasi steady state, it is possible to localise the zones of the slope potentially subjected to flow sliding.