Brittleness is an important property of rocks in the context of engineering applications, as it often determines how severe the practical consequences of rock yield will be. Many authors have proposed various brittleness indices intended to allow for relative categorization of brittleness, but many are relatively simplified and/or only applicable for certain categories of rock. This study provides a new perspective on rock brittleness through study of the confining stress at the brittle–ductile transition. Based on previous findings regarding the brittle–ductile transition, an equation to predict this confining stress is derived, and three key material properties associated with material brittleness are identified. Considering these properties, existing assumptions regarding material brittleness as applied in the rock mechanics literature are identified and discussed. A preliminary analysis of data from the literature regarding the influences of fluid saturation and true triaxial loading conditions is presented.

在工程应用的背景下，脆性是岩石的一个重要特性，因为它通常决定了岩石屈服的实际后果的严重程度。许多作者提出了各种脆性指数，旨在允许对脆性进行相对分类，但许多相对简化和/或仅适用于某些类别的岩石。本研究通过研究脆-韧转变处的围压，为研究岩石脆性提供了新的视角。基于之前关于脆-韧转变的发现，推导出了预测这种围压的方程，并确定了与材料脆性相关的三个关键材料特性。考虑到这些特性，确定并讨论了在岩石力学文献中应用的关于材料脆性的现有假设。对文献中有关流体饱和度和真实三轴载荷条件影响的数据进行了初步分析。