Soil pipes and slope stability

Abstract

Summary Experimentation with a Hele-Shaw viscous-flow analogue apparatus has supported earlier suggestions, based on field evidence, that a causal link may exist between some soil pipes and slope failure. The analogue has shown that when a pipe is blocked or is a dead-end passageway (a closed pipe), the cavity can readily fill with water during rainstorms. Pipes partially filled with standing water will generate pore pressures in the surrounding soil matrix in proportion to the hydrostatic head achieved. Long pipes parallel to the fall line of the slope have the potential, when partially filled with water, of generating soil pore-water pressures much greater than those generated by total saturation of the soil. Such pore-pressure increases could trigger landslides at sites that would otherwise be stable.