A quantitative model of dilatancy in dry rock and its application to westerly granite
A quantitative model of dilatancy in dry rock and its application to westerly granite
复制标题
干岩剪胀定量模型及其在西风花岗岩中的应用
DOI：
10.1029/jb083ib10p04941
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发表时间：
1978
影响因子：
--
通讯作者：
D. Holcomb
中科院分区：
文献类型：
--
作者：
D. Holcomb
基于单个微裂纹的行为，建立了一个通用的裂纹扩展模型。宏观效应通过使用统计方法结合单个裂纹的影响来描述。该模型是使用分布函数的裂纹尺寸，裂纹强度和局部应力。部分卸载和再加载的体积应变和应力应变数据的滞后一般加载路径可以描述。该模型是最适合于描述岩石已受到一定数量的负载循环足以消除残余体积应变，是目前在初始周期。这使得岩石更能代表真实的地球，并消除了阻碍反射效应的瞬态效应。在0 ~ 4.11kbar的围压范围内，该模型能很好地描述西风花岗岩三轴实验的体应变数据。仅需一个参数来描述围压变化的影响，这可以解释为裂纹体积的弹性效应。解释这些数据所必需的裂纹行为的某些方面与通常的滑动裂纹模型不相容。结合缺乏可观察到的剪切裂纹，这对滑动裂纹模型的有效性提出了严重的质疑。«少
A general model of dilatancy was developed based on the behavior of individual microcracks. Macroscopic effects were described by combining the effects of individual cracks using a statistical approach. The model was developed using distribution functions for crack size, crack strength, and local stress. Hysteresis in volumetric strain and stress-strain data for partial unloading and reloading the general loading paths can be described. The model is best suited to describing rock which has been subjected to a number of loading cycles sufficient to remove the residual volumetric strain that is present in the initial cycles. This makes the rock more representative of the real earth and removes transient effects that obcure the dilatant effect. Volumetric strain data from triaxial experiments on Westerly granite were well described by the model for confining pressures from 0 to 4.11 kbar. Only one parameter was needed to describe the effect of changing the confining pressure, and this can be interpreted as an elastic effect on the crack volume. Some aspects of crack behavior that were necessary to explain the data are incompatible with the usual sliding crack model of dilatancy. Combined with the lack of observable shear cracks, this casts serious doubts on themore » validity of the sliding crack model.« less