Abstract:Triaxial compression experiments are carried out for marble specimens by servo-controlled testing machine. After the specimens failed,they were then completely unloaded;and then uniaxial compression tests were carried out for the damaged rock specimens. Based on the experimental results,the plastic deformation and energy properties of marble specimens are analyzed under different confining pressures. At the same time,the uniaxial strength,elastic modulus and energy property of damaged specimens after unloading are investigated. The results show that marbles process the clear BDT(brittle-ductile transformation) property. The stress-strain curve shows the yield platform under higher confining pressure,i.e. the plastic deformation of rock specimen continues to increase with the axial deformation,but the supporting capacity by friction keeps basically a constant. The dissipated energies of rock specimens before yielding are comparatively less in the process of triaxial compression,but more energies in the process of plastic deformation. Moreover,the plastic deformation of rock specimen has a good linear relationship with the dissipated energy. Under high confining pressure,rock specimen will dissipate more energy in order to make the specimen fail completely. The strength and elastic modulus of the damaged specimens decrease linearly with the increase of plastic deformation. The produced plastic deformation under lower confining pressure has distinct effect on the strength and elastic modulus. However,in the yielding and softening phases after peak strength,the decrease of the supporting capacity of rock specimen is linearly accorded with the increase of plastic deformation. The softening modulus and elastic modulus of damaged specimens have no clear relationship with the peak strength,showing the localized behaviors of failure.