Experimental study on progressive yielding of marble

摘要

Cyclic loading experiments were widely used to study the progressive yielding of rock-likenmaterials. For brittle rocks, around the peak stress or in the post-peak region, brittle failurenoccurred as soon as the axial stress was unloaded. In order to conduct the cyclic loading aroundnand after peak stress, a new loading method was proposed based on the elastic–plastic theory.nComparison between the results of conventional triaxial compression tests and cyclic loadingntests showed that the new loading method had little influence on the yielding process of marble.nBased on the results of cyclic loading tests, a plastic internal variable was defined which took theninfluence of confining stress on the yielding process into consideration. Then, the variation ofnelastic parameters was obtained according to the plastic internal variable. The result showed thatnwhen the rock underwent plastic deformation, shear modulus progressively decreased while thenbulk modulus changed slightly. The efforts of this paper can provide basic data for future study ofnthe mechanical model of brittle rock.