New theory of rock fracture based on interaction between pre-existing

利用在计算机上建立的单矿物多晶岩石试件模型，我们进行了单轴拉伸断裂分析和由于应力解除过程中晶界的粘弹性行为而导致的岩石损伤估计。在前者中，我们阐明了破坏机制，使得破坏模式从拉伸到剪切的转换总是发生在最终破坏面的完成过程中。在后者中，用DSCA方法可以准确地估计主应力的大小和方向的应力区，并且这个区域随着深度的增加而变宽。因此，我们现在可以通过扩展应力条件来建立一种新的岩石断裂理论。

Using specimen models of monomineral polycrystalline rock created on a computer, we performed both analysis of uniaxial tensile fracture and estimation of rock damage due to the viscoelastic behavior of grain boundaries during stress relief. In the former, we have clarified fracture mechanisms such that the conversion of failure mode from tension to shear always occurs during the completion of the final failure plane. In the latter, it has been shown that there is a stress region for which both the magnitudes and directions of the principal stresses can be accurately estimated by DSCA and this region becomes wider as the depth increases. Thus, we can now approach to the construction of a new theory of rock fracture by extending stress conditions.