Аннотация:A paper considers mathematical model, numerical method and its software implementation on GPU for the simulation of the development and localization of plastic shear bands in a poroelastoplastic solid. A mathematical model of the process is described by a system of nonlinear partial differential equations of poroelastoplasticity, generalizing the Biot model for a two-phase fluid-saturated poroelastoplastic medium. A nonlinear dependence of material parameters on a dynamic porosity, which, in turn, depends on the volumetric deformation of the skeleton, is taken into account. For the numerical solution of the posed problem an isoparametric spectral element method is used to discretize a geometric model and poroelastoplastic equations in space on curvilinear unstructured meshes. A dynamic relaxation method is used to obtain a stationary solution of the boundary value problem using an explicit time scheme, which leads to a high scalability of the computational process when parallelizing the algorithm on massively parallel GPU. The algorithm is implemented using CUDA technology. A spectral element mesh is naturally mapped onto the CUDA Grid, and accordingly, each spectral element is mapped onto a CUDA Block, so local nodes inside a spectral element are processed by the threads in the Block. This approach allows efficient use of the shared memory for data caching in the Block and significantly increase the throughput of the parallel algorithm, which is essentially memory bound. Numerical results of the simulation of the development and localization of plastic shear bands nearby a borehole drilled in a porous fluid saturated solid are presented. Evolution of porosity and permeability as a result of the accumulation of plastic deformations is analyzed.