岩石损伤过程中的渗流特性

目前人们对岩石损伤后渗透性变化定性、定量方面的认识都存在不足，通过分析中国大量岩石全应力应变过程渗透性试验的成果，总结出目前岩石破损过程渗透性变化的4种类型。分析了岩石孔隙、裂隙、岩性等因素对于形成4种不同渗透性变化类型的影响，以及围压对渗透性发展演化的作用。峰值前一般渗透性随围压增加而减小，但峰后比较复杂，值得继续研究。统计分析了目前试验中岩石渗透性的变化范围，结果表明：一般软岩渗透性变化较小，脆性岩石渗透性变化较大。从目前围压1MPa-40MPa的全应力应变渗透性试验结果来看，97％渗透性变化不超过1000倍，其中85．9％渗透性变化不超过100倍。提出岩石破坏后是否出现高速非达西流需要从有效应力考虑，提出了渗流失稳与渗流作用下结构失稳的区别。

Seepage Characteristics of Rock during Damage Process

Four evolution patterns of rock permeability in damage process are summarized. And how rock pore, micro cracks and lithology form the four patterns of rock permeability evolution is analyzed. The impact of confining pressure on permeability is also presented. The permeability reduces along with the increase of confining pressure before rock failure, however, it is complex after rock failure, and it is necessary to do further research. Statistical analysis is carried out to analyze the variation range of permeability in the process of damage, which shows soft rocks vary less while hard rocks vary more. In the experiments in which the confining pressure is between 1 MPa to 40 MPa, permeability variation of 85.9 % rock is within 100 times, 97% within 1000 times. Furthermore, the difference between instability of seepage and that of structure under the function of seepage is distinguished. It is proposed that the presence or absence of non-Darcy flow should be considered from the point of effective stress law.