This Paper describes an analysis of the quasi-static penetration of a cone penetrometer into clay. The clay is idealized as a homogeneous elastic–perfectly plastic material obeying tbe von Mises yield criterion. The analysis is based on the strain path method, with an additional equilibrium correction provided by large strain finite element analysis. The dissipation of excess pore water pressure is analysed using uncoupled Terzaghi–Rendulic consolidation theory. The primary importance of the rigidity index and of the horizontal stress in influencing the cone factor Nkt, is emphasized and an equation relating Nkt to soil parameters and cone roughness is proposed. Based on finite difference analysis of the pore pressure dissipation around the cone, a new interpretation method for consolidation data from a piezocone is suggested. Cet article décrit une analyse de la pénétration quasi-statique d'un pénétromètre dans I'argile. L'argile est considérée de façon idéalle comme une matière homogène élastique parfaitement plastique et qui satisfait le critèe d'écoulement de von Mises. L'analyse est basée sur la méthode des chemins de déformation, avec une correction suppémentaire de I'équilibre fournie par I'analyse en éléments finis des déformations importantes. À I'aide de la théorie de consolidation non-couplée de Terzaghi–Rendulic on analyse la dissipation de la pression excédentaire de I'eau interstitielle. L'article souligne I'influence essentielle exercée sur le facteur de cône Nkt par I'indice de rigidité et la contrainte horizontale. Il est proposée une équation qui lie Nkt aux paramktres de sol et à la rugosité du cône. On propose une nouvelle méthode d'interprétation des données de consolidation à partir du piezocône hasée sur I'analyse différentiel-le finie de la dissipation de la pression de I'eau interstitielle.

This study numerically investigates the influence of material heterogeneity on the strength and deformation behavior and the associated microcracking process of a felsic crystalline rock using a grain‐based modeling approach in two‐dimensional Particle Flow Code. By using a heterogeneity index defined in this study, the heterogeneity induced by variation of grain size distribution can be explicitly incorporated into the numerical specimen models quantitatively. Under compressive loading, the peak strength and the elastic modulus are found to increase as the numerical model gradually changes from heterogeneous to homogeneous, i.e., a decrease of heterogeneity index. Meanwhile, the number of grain boundary tensile cracks gradually decreases and the number of intragrain cracks increases at the moment of failure. However, the total number of generated microcracks seems not to be significantly influenced by heterogeneity. The orientation of grain boundary microcracks is mainly controlled by the geometry of assembled grain structure of the numerical specimen model, while the orientation of intragrain microcracks is to a large degree influenced by the confinement. In addition, the development of intragrain cracks (both tensile and shear) is much more favored in quartz than in other minerals. Under direct tensile loading, heterogeneity is found to have no significant influence on the simulated stress‐strain responses and rock strength. Only grain boundary tensile cracks are generated when the numerical models are loaded in direct tension, and the position of generated macroscopic fracture developed upon failure of the specimen is largely affected by heterogeneity.

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