Understanding the control mechanism of fault rock particle size in fluid-induced fault slip and rupture processes is crucial for mitigating the seismic risks associated with large-scale fluid injection. Here, we conducted laboratory experiments to present the effects of fault rock particle size on slip behavior, friction, and slip modes under fluid injection. Our results demonstrate that the particle size of the gouge controls the initiation of fault slip events and that the fluid pressure required for the initial fault slip is negatively correlated with the rock particle size. The increase in rock particle size can weaken the faults and induce the transition of the fault slip mode from creep to slow stick-slip events, which leads to the occurrence of seismic events. These results reveal the particle size of fault gouge exerts a potentially dominant control on the slip behavior, slip modes, and frictional characteristics of faults under fluid injection, providing crucial insights into fault slip and seismic events.

中文翻译：

---

流体喷射下故障过孔的粒径控制的故障滑移行为和摩擦稳定性


了解流体诱导的断层滑移和破裂过程中断层岩石粒径的控制机制对于减轻与大规模流体注入相关的地震风险至关重要。在这里，我们进行了实验室实验，以展示断层岩石粒度对流体注入下滑移行为、摩擦和滑移模式的影响。我们的结果表明，凿孔的粒径控制着断层滑移事件的发生，并且初始断层滑移所需的流体压力与岩石粒径呈负相关。岩石粒径的增加会削弱断层，诱发断层滑移模式由蠕变转变为慢粘滑事件，从而导致地震事件的发生。这些结果表明，断层凿切的粒径对流体注入下断层的滑移行为、滑移模式和摩擦特性具有潜在的主导控制作用，为断层滑移和地震事件提供了重要的见解。