Abstract
In order to clarify the influence of confining stress, void ratio and particle breakage on the dynamic deformation characteristics of volcanic soils, some site investigations (e. g. standard penetration test and seismic cone penetration test) and cyclic undrained triaxial tests on undisturbed and reconstituted samples were carried out. The test results showed that the effect of confining stress on shear modulus G for crushable volcanic soils is more remarkable than Toyoura sand. However, confining stress-dependency of damping ratio h for crushable volcanic soils becomes less pronounced. Also, G values of crushable volcanic soils, consisting mainly of brittle pumice, are less dependent on void ratio than sand and Shirasu. Moreover, cementation effect in the volcanic ground on the dynamic properties for small strain level was detailedly discussed.
