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Abstract Based on the results of cyclic loading and unloading tests of two kinds of deep marbles and from Jinping II hydropower station，an elastoplastic coupling mechanical model considering confining pressure effect is proposed with taking the following aspects into consideration：(1) Evolution of elastic parameters of marbles with internal variable under different confining pressures is studied；and the quantitative relationships among elastic modulus，confining pressure and internal variable are proposed. (2) On the basis of Mohr-Coulomb yield criterion，the variation of strength parameter with internal variable is put forward. (3) Evolutions of dilatancy angle of Jinping marbles with internal variable and confining pressure are analyzed considering non-associated flow rule；and the quantitative relationships among dilatancy angle，confining pressure and internal variable are proposed. (4) Finally，the proposed mechanical model is embedded in FLAC3D using C++ language，and used to simulate the conventional triaxial compression test results. It is shown that there is significantly better agreement between simulating results and test data，and the proposed mechanical model can reflect the main mechanical properties of marbles. Efforts of this paper can give an important reference for promoting numerical accuracy of deformation and stability for rockmass of deep engineering，especially for brittle rockmass with the characteristics of fracturing under small deformation.
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Received: 24 May 2012
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2012, Vol. 31 
