Abstract
It is common practice to cover railway embankment slopes with protective materials to prevent rain-induced slope failure. Although slope covering of this type is designed mainly for erosion control, it also has the effect of helping prevent the groundwater level rising through the embankment body in the event of heavy rain. This study investigates the groundwater level lowering effect of protective covering over the upper half of the slope of a railway embankment made of sandy material, and the factor of safety of the slope that can be achieved by such slope covering. A numerical analysis parameterizing such factors as embankment height and slope covering length is conducted, and the effect of slope covering on slope failure due to heavy rain is investigated quantitatively. The study has revealed that upper surface covering over an embankment slope helps prevent rain-induced slope failure. This paper also proposes a procedure for applying these results to a risk evaluation method based on critical rainfall.
