The wetting deformation is one of the leading long-term deformations of the earth-rockfill dam

which significantly influences the stress-deformation behaviours of the dams. In this paper

the rockfill material of weakly weathered granite from the Nuozhadu high earth-rockfill dam was studied by conventional triaxial tests

combined creep-wetting tests

and quick-wetting (without creep stage) tests under different confining pressures and stress levels. The deformation behaviours at all stages of the combined creep-wetting tests were analysed

and the evolution process

characteristics

and mechanism of wetting deformation were investigated. Results show that the wetting deformation of the rockfill material can be classified as the instantaneous wetting deformation and the wet-state creep deformation. The instantaneous wetting deformation occurs during the process of wetting and saturating of the rockfill material and shows non-hardening characteristics. Moreover

the strain increment direction is parallel to the direction of the loading-induced strain increment at the same stress state. The wet-state creep deformation occurs after the rockfill material is saturated and has similar characteristics to the general creep deformation of rockfill materials. The wetting deformation is induced by the weakening of physical state after the rockfill material is wetted by water

and thus the wetting of rockfill material can be considered as a generalised load.