Based on rock meso-damage and fracture mechanism, it is presented that the crack growing is the removal process of damaged zone due to the gradual damage from the crack tip to the around rock.

• 基于岩石细观损伤断裂理论，认为裂纹扩展的过程就是裂纹尖端到周围岩石的逐渐损伤引起的损伤区移动过程；