Digital Rock Physics has reached a level of maturity on the characterisation of primary properties that depend on the microstructure – such as porosity, permeability or elastic moduli – by numerically solving field equations on μCT scan images of rock. After small deformations or at depth though, most rocks eventually reach their limit of elasticity and the complementary plastic properties are needed to describe the full mechanical behaviour. Currently, determination of a rock’s yield surface from its microstructure is often restricted to semi-analytical criteria derived by limit analysis or numerical simulations performed on idealised geometries. Such simplification lacks representativeness, particularly for processes that affect directly the pore-grain interface such as the cementation phenomenon, happening during diagenesis. Eventually, only direct numerical simulation of elasto-plasticity performed on digitalised microstructures can be used to assess the strength of different cemented materials and its evolution with the alteration of the microstructure. In this study, we provide a comprehensive parametric study on the impact of cementation on rock strength for real microstructures of cemented granular materials. Compared to most previous studies, the whole yield surface is determined numerically (using Finite Element Method) in order to assess the influence of cementation for different stress-paths. The previously known tendency of rock to strengthen with increasing cementation volume is verified. New results on the influence of cement property namely Young’s modulus, friction and cohesion on the rock’s yield surface are explored. The envelopes obtained are compared to the ones obtained by experimental data and existing models. The framework presented in this study showcases the wider possibility of determining any rock’s or porous material’s yield surface from its microstructure.

数字岩石物理学通过数值求解岩石的 μCT 扫描图像上的场方程，在表征取决于微观结构的主要特性（例如孔隙率、渗透率或弹性模量）方面已经达到了一定程度的成熟度。然而，在小变形或深度之后，大多数岩石最终会达到其弹性极限，并且需要互补的塑性特性来描述完整的机械行为。目前，从微观结构确定岩石的屈服面通常仅限于通过极限分析或对理想几何形状进行的数值模拟得出的半分析标准。这种简化缺乏代表性，特别是对于直接影响孔-粒界面的过程，例如在成岩过程中发生的胶结现象。最终，只有在数字化微观结构上进行的弹塑性直接数值模拟才能用于评估不同胶结材料的强度及其随微观结构变化的演变。在这项研究中，我们针对胶结颗粒材料的真实微观结构提供了胶结对岩石强度影响的综合参数研究。与大多数以前的研究相比，整个屈服面是通过数值确定的（使用有限元方法），以评估胶结对不同应力路径的影响。验证了先前已知的岩石随着胶结体积的增加而增强的趋势。探讨了水泥性质即杨氏模量、摩擦力和内聚力对岩石屈服面影响的新结果。将获得的包络与通过实验数据和现有模型获得的包络进行比较。本研究中提出的框架展示了从微观结构确定任何岩石或多孔材料的屈服面的更广泛的可能性。