USING A COMBINED SLOPE HYDROLOGY-STABILITY MODEL TO DEVELOP CUT SLOPE DESIGN CHARTS.

Slope instability in the tropics is often attributed to the effect of rainfall infiltration - the dynamic hydrological condition controlling stability. This paper describes a physically based, coupled, two- dimensional slope hydrology-slope stability model that has been developed to investigate this control. Model predicted hydrological conditions are used as input to a stability analysis sub-model capable of accounting for the effects of both pore pressures and suctions on stability. Application of the combined model to a range of slope forms and antecedent conditions allows the production of 'design charts' which summarize the effect of particular storm events on slope stability. It is envisaged that the developed scheme will be of considerable utility where rainfall induced instability is the principal cause of slope failure.