Cyclic softening of volcanic-ash cohesive soils

Abstract

The analysis of undrained cyclic triaxial tests followed by monotonic undrained shear on volcanic-ash cohesive soils shows that double amplitude shear strain is a more suitable cyclic damage parameter for evaluating mechanical degradation than excess pore water pressures. Although there is a good correlation between excess pore water pressures and double amplitude shear strain generated during undrained cycling, using shear strain provides a more precise assessment of cyclic damage. This finding emphasizes the importance of selecting properly the right parameters for accurate evaluations in cyclic softening of fine-grained saturated soils.