亚临界裂纹扩展是岩体工程时间相依性的主要原因之一，利用Inston1342型电液伺服材料试验机，采用常位移松弛法分别进行自然状态以及饱水状态下岩块的亚临界裂纹扩展实验，获得了两种环境下岩石裂纹扩展速率v 与应力强度因子KI的关系及亚临界裂纹扩展参数，研究水对岩石亚临界裂纹扩展规律的影响，并对两种环境下亚临界裂纹扩展参数进行了对比分析。结果表明：两种环境下岩石的lgK I−lgv有较好的线性规律，岩石的亚临界裂纹扩展速率与裂纹尖端应力强度因子服从幂函数关系；在双对数坐标空间中，含饱和水试件的lgK I−lgv曲线位于空气中试件lgK I−lgv曲线的左上角，含饱和水试件的曲线斜率较空气中试件的减小，而截距增加。在同一应力强度因子水平上，含饱和水试件的裂纹扩展速度大，表明水加速了岩体亚临界裂纹扩展。该实验结果可为水化学作用下复杂岩体的稳定性分析提供可靠依据。%Subcritical crack growth is one of the main causes of time-dependent behavior in rock mass engineering. By using Instronl 1342 type electro hydraulic servo test machine and adopting the double-torsion load-relaxation method at constant displacement, two groups of specimens, one immersed in groundwater and the other in air, were tested to study the relationship between the crack growth ratev and fracture toughnessKI, and the parameters of subcritical crack growth in the two different environments were gotten. The influence of water on the subcritical crack growth mechanism was analyzed, and comparisons of the parameters of the growth of subcritical crack were made for the two different environments above-mentioned.The results show that the parameters of lgKI−lgv are in accord with linear rules, the relationship between subcritical crack growth velocityvand stress intensity factorKI agrees power function. In the double logarithmic coordinates space, the lgKI−lgvcurves of those specimens in saturated water locate at the left coner above those of the specimens in air with smaller slope but larger intercept. In addition, the subcritical crack growth velocity of saturated water specimen is higher at the same stress intensity factor, which indicates that water speeds up the subcritical crack growth. Those results can provide reliable references to study the complicated rock mass stability under the effects of water.
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