Cyclic undrained behaviour of sand with different fines content was investigated through stress-controlled cyclic triaxial testswith partial stress reversal. The test results were analysed based on the concept of equivalent granular state parameter, Ψ*. Three differenttypes of behaviour were observed: namely cyclic instability, cyclic mobility and an in-between transition behaviour. Cyclic instability wasobserved for loose sand-fines mixtures with a positive Ψ*, and can be related to the instability stress ratio of monotonic test with sameequivalent granular void ratio, e* as long as instability was controlled by the compression side of the stress space. On the other hand, cyclicmobility was observed for samples had negative Ψ*. However, transition behaviour was observed for samples with Ψ* values close to zero.
展开▼
