The presence of fractures in rock masses plays a major role in its stress state and its variability. Each fracture potentially induces a stress perturbation, which is correlated to its geometrical and mechanical properties. This work aims to understand and quantitatively predict the relationship between fractured systems and the associated stress fluctuations distribution, considering any regional stress conditions. The approach considers the rock mass as an elastic rock matrix into which a population of discrete fractures is embedded—known as a Discrete Fracture Network (DFN) modeling approach. We develop relevant indicators and analytical solutions to quantify stress perturbations at the fracture network scale, supported by 3D numerical simulations, using various fracture size distributions. We show that stress fluctuations increase with fracture density and decrease as a function of the so-called stiffness length, a characteristic length that can be defined as the ratio between Young’s modulus of the matrix and fracture stiffness. Based on these considerations we discuss, depending on DFN parameters, which range of fractures should be modeled explicitly to account for major stress perturbations in fractured rock masses.

岩体中裂缝的存在对其应力状态及其变化起着重要作用。每个断裂都可能引起应力扰动，这与其几何和机械性能相关。这项工作旨在考虑任何区域应力条件，了解并定量预测裂缝系统与相关应力波动分布之间的关系。该方法将岩体视为弹性岩石基质，其中嵌入了一组离散裂缝，称为离散裂缝网络 (DFN) 建模方法。我们开发了相关指标和分析解决方案，以量化裂缝网络规模的应力扰动，并在 3D 数值模拟的支持下，使用各种裂缝尺寸分布。我们表明，应力波动随着裂缝密度的增加而增加，并作为所谓的刚度长度的函数而减少，刚度长度是一种特征长度，可以定义为基体的杨氏模量与断裂刚度之间的比率。基于这些考虑，我们根据 DFN 参数讨论，应该对哪些裂缝范围进行明确建模，以考虑裂缝岩体中的主要应力扰动。