Undrained monotonic shear behaviour of suffusional volcanic ash

Abstract

Suffusion is characterised as seepage induced loss of fine particles with no change in volume and an increase of hydraulic conductivity. The degree of migration of fine particles can affect both micro and macro structural behaviour of soil. This paper analyses the impacts of suffusion on the mechanical properties of widely graded volcanic soil with different relative densities in triaxial compression. It was observed that effects on the undrained mechanical behaviour of the soil were also dependent on the initial density of the specimen, with changes in the small strain stiffness, stress-strain relationship and soil dilatancy.