Abstract
The increments in compressive displacement and the stress increase of a sandy slope due to the growth of subsurface flow during rainfall were theoretically examined. Both the stress variation and the displacement equations were derived based on the assumption that the slope was a compressible continuum, which was in proportion with the power of stress. These equations provided schematically their distribution patterns of stress and compressive displacement in a slope at a certain time. The model simulation under a constant rainfall intensity indicated that the compressive displacement drew a rise curve, but the increment decreased with time, and the stress became constant gradually from the top of slope with time since the steady zone of the subsurface flow expanded from the top of the slope. The equilibrium of the compressive force and the critical passive earth pressure at the foot of the slope enable both the prediction of failure time and the evaluation of compressive displacement preceding the slope failure. Finally the transition point from the above compression stage to the initiation of slope failure was discussed on the basis of the characteristics of compressive displacement and its velocity curves.
