Large-deformation localized failure in geomaterials plays a crucial role in geohazards engineering. This article investigates shear bands and retrogressive failure of geomaterials through a recently formulated large-deformation-plasticity periporomechanics (PPM) paradigm. Periporomechanics is a nonlocal reformulation of classical poromechanics through the effective force and peridynamic state concepts. The nonlocal deformation gradient is multiplicatively decomposed into the elastic and plastic parts in this large-deformation PPM paradigm. The stabilized correspondence principle is adopted to implement a classical elastoplastic constitutive model into the new PPM paradigm. We have numerically implemented this large-deformation plasticity PPM paradigm through a Lagrangian meshfree method in space and an explicit Newmark scheme in time. The implemented PPM framework is used to model shear banding and retrogressive slope failure in porous media under dry conditions. The numerical results have demonstrated the efficacy and robustness of this new PPM paradigm for modeling shear banding and retrogressive failure involving large deformation in porous media.

翻译：岩土材料的大变形局部破坏在地质灾害工程中具有关键作用。本文通过新近提出的大变形塑性近场孔隙力学范式，研究岩土材料的剪切带与渐进式破坏。近场孔隙力学是基于有效力与近场动力学状态概念对经典孔隙力学的非局部重构。在此大变形PPM范式中，非局部变形梯度被乘法分解为弹性与塑性两部分。采用稳定对应原理将经典弹塑性本构模型嵌入新的PPM范式。我们通过空间中的拉格朗日无网格方法与时间上的显式Newmark格式，实现了该大变形塑性PPM范式的数值计算。所实现的PPM框架用于模拟干燥条件下多孔介质中的剪切带形成与边坡渐进式破坏。数值结果验证了该新PPM范式在模拟多孔介质大变形剪切带与渐进式破坏方面的有效性与鲁棒性。