Rock mass classification systems are used to categorize and estimate the role of the most significant parameters influencing rock mass behavior to represent an equivalent continuum. Generally, in these methods, the impact of the related parameters is considered uniform in all directions. Hence, these systems describe the rock mass as an isotropic medium. In some cases, in particular, for layered strata and systematically fractured rocks, the assumption of isotropic behavior may not provide realistic results. Hence, in this paper, to characterize the rock mass anisotropy, a directional rock mass rating (DRMR) has been proposed based on the well-known rock mass rating (RMR). So, DRMR provides a three-dimensional rock mass rating, quantitatively. By means of statistical distribution of DRMR, a classification for the degree of anisotropy of rock mass has been proposed. Furthermore, a criterion to identify the prominent rock mass, isotropic/transversely isotropic/anisotropic situation, is presented. Then the stereonet has been used to demonstrate an all-round graphical representation of DRMR. This with DRMR provides an illustrative insight into the actual rock mass condition and can assist to select the appropriate method for further analysis. Also, the method can be used as a basis to develop practical solutions for many rock engineering issues, such as characterizing the mechanical parameters of rock mass as an anisotropic equivalent continuum, selective directional rock mass improvement, and proper selection of rock tunnel and rock cavern alignments. Finally, the results of some practical applications of the method, based on field data, are presented.

岩体分类系统用于分类和估计影响岩体行为的最重要参数的作用，以代表一个等效的连续体。通常，在这些方法中，相关参数的影响被认为在所有方向上都是一致的。因此，这些系统将岩体描述为各向同性的介质。在某些情况下，尤其是对于分层的地层和系统破裂的岩石，各向同性行为的假设可能无法提供现实的结果。因此，在本文中，为了表征岩体各向异性，已经基于众所周知的岩体额定值（RMR）提出了定向岩体额定值（DRMR）。因此，DRMR定量地提供了三维岩体评级。通过DRMR的统计分布，已经提出了岩体各向异性程度的分类。此外，提出了识别主要岩体的标准，即各向同性/横向各向同性/各向异性情况。然后，使用了立体声网络来演示DRMR的全面图形表示。使用DRMR可以提供对实际岩体状况的说明性见解，并且可以帮助选择适当的方法进行进一步的分析。此外，该方法可被用作基础来开发用于许多岩石工程问题，例如岩体的力学参数作为各向异性等效连续，选择性定向岩体的改善，和岩石隧道和岩洞的适当选择表征实际的解决方案对齐方式。最后，该方法的一些实际应用的结果，