三轴应力下岩石蠕变扩容的微裂纹扩展模型

A MICROCRACKS EXTENSION MODEL FOR CREEP DILATANCY OF ROCK UNDER TRIAXIAL STRESSES

本文引入一个简单模型来分析三轮应力下岩石的蠕变扩容机制．模型描述了蠕变过程中岩石中已存在的微裂纹随时间起裂、扩展和连接．分析表明，进裂纹端点处的应力集中、能量耗散和它们的相互作用是微裂纹扩展的主要因素．由理论分析得到的微裂纹扩展速率与岩石典型蠕变曲线特征互相吻合．

A simple model is used to analyze the mechanism of creep dilatancy.The model describes the initiation,propagation and linkage of microfracture from pre-existing microcracks.The analysis shows that the concentration of stresses and dissipation of energy at the tip of the microcracks and their interaction are major causes of microcracks extending during creep process.The velocity ofmicrocrack growth computed by the theory is well agreeable to the character of typical experimental creep curve.