Experimental investigation and constitutive modelling for an unsaturated pyroclastic soil

摘要

The paper deals with the mechanical behaviour of an unsaturated air-fall volcanic (pyroclastic)rnsoil, originated by the explosive eruptions of theVesuvius volcano in southern Italy. Some experimental laboratoryrntests are described with special reference to theWater Retention Curve (WRC) and the Critical State Line (CSL);rnand, a series ofwetting-collapse suction-controlled oedometric tests are illustrated. Then, a Generalized Plasticityrnconstitutive model is calibrated referring both theWRCand CSL, and is used to simulate the experimental resultsrnof the wetting-collapse tests. The numerical results match the experimental evidences reasonably well, becausernthe constitutive model properly simulates the suction-related bonding effect among the solid grains.