The deep slide of gravity dam is mainly reflected in the appearance of sliding channel along the slow-inclination of weak structure plane. The strain accumulates in sliding channel with very sharp discontinuous strain gradient is a typical strain localization phenomenon. The classic continuum theory suffers from the pathological mesh-dependence in strain localization problem of strain softening material in failure analysis. In this contribution

the governing field equations are regularized by adding rotational degrees-of-freedom to the conventional translational degrees-of-freedom and an elastoplastic Mohr-Coulomb model is presented based on the Cosserat continuum theory

in addition

non-associated flow rule is adopted. In the framework of classic plastic theory

the backward Euler algorithm is used to update plastic stress. A uniaxial compression is performed; the numerical results show that the load-displacement curves are uniformly converged upon different mesh sizes and mesh-independence solutions can be obtained. Finally

the overloading method is adopted in the gradually destruction process simulation analysis. The simulation results show that the classical continuum theory has salient mesh-dependence and are inclined to risk; otherwise the Cosserat theory is more reasonable.