Rock mass surrounding the excavation also under the complex radial unloading and ring direction loading stress path due to the excavation

for which results in difference from that of rock mass strength，deformation property and failure mechanism. Aiming to the high in-situ stress characteristics of Jinping II hydropower station

four different stress paths are chosen as test schemes corresponding as the uniaxial compressive test

triaxial compressive test

unloading triaxial test and unloading confining – loading axial pressure full test under high stress conditions are carried out on the marble specimens from the drainage tunnel. The complete stress-strain curve，deformation properties，failure characteristics and limited energy storage are obtained under respective stress path. Some instructive conclusions are drawn from tests as follows: (1) The failure axial strain is generally small. Jinping marble is hard and brittle which more apparent under unloading conditions. (2) The axial strain

circumferential strain and volumetric strain value unloading confining – loading axial pressure full tests are generally higher in the unloading tests

peak strength conversely. (3) The deformation modulus is large and the peak strength is lower with larger unloading rate

the deformation modulus is lower and the peak strength is large with larger loading rate

the deformation modulus is lower and the peak strength is large with larger initial confining pressure. (4) The principally failure model is tension without confining pressure; shear failure and locally tensile failure with lower confining pressure; while shear failure shape is X or Y with higher confining pressure. (5) The rock specimens have the limited value of energy storage

which can be effected by various factors. Limited energy storage is large with high confining pressure and is lower with higher unloading stress rate. The results can offer valuable references in explaining the mechanism of rockbutst and solving underground rock engineering problems.