Fracture initiation and propagation in fluid-saturated rocks are controlled by interaction between fluid flow and rock deformation. The description of hydromechanical coupling is essential for modeling the fracture process. In this paper, an improved hydromechanical model is proposed in the framework of the particle flow simulation method. This model provides a better description of hydraulic properties before and after breakage of bonds and can efficiently describe fluid flow through porous rock matrix and along fractures. The efficiency of the proposed model is first assessed by comparisons with analytical solutions and typical experimental evidences. A series of numerical simulations are then realized to investigate effects of some key parameters such as confining stress, fluid injection rate and viscosity on the initiation and propagation of fractures.

流体饱和岩石中的裂缝起裂和扩展受流体流动和岩石变形之间的相互作用控制。流体力学耦合的描述对于模拟断裂过程至关重要。本文在粒子流模拟方法的框架内提出了一种改进的流体力学模型。该模型更好地描述了键断裂之前和之后的水力特性，并且可以有效地描述通过多孔岩石的流体流动基质和沿裂缝。首先通过与解析解和典型实验证据的比较来评估所提出模型的效率。然后通过一系列数值模拟来研究一些关键参数，如围压、流体注入速率和粘度对裂缝的萌生和扩展的影响。