ABSTRACT
As strain softening constitutive behavior is incorporated into a computational model in the frame of classical plastic continuum theories, the initial and boundary value problem of the model will become ill-posed, resulting in pathologically mesh-dependent solutions. Based on pressure-dependent elastoplastic Cosserat continuum model, progressive failure phenomena of the Senise slope occurred in the excavation processes, characterized by strain localization due to strain softening, are numerically simulated. One of the radical approaches to introduce the regularization mechanism into the model is to utilize the Cosserat micro-polar continuum theory, in which high-order continuum structures are introduced. Numerical results indicate the inability of classical continuum model in simulating the whole failure progress, while the capability and performance of Cosserat continuum model in keeping the wellposedness of the boundary value problems with strain softening behavior incorporated and in completing simulation of the whole failure progress.
