Abstract An accurate description of the morphology of a joint surface is necessary to interpret its shear behavior. Accurately distinguishing the shear behavior differences may be difficult if the defined morphology parameter ignores the micro-slope distribution of the joint surface. The initial climbing angle was therefore defined and used to characterize the micro-slope distribution of the ascent section of joint profile, and a new method was proposed for calculating the morphology parameter, M. The parameter M embodies anisotropy, and the values of M for all profile lines, which are selected on the same joint at equal intervals in one direction, are log-normally distributed. To study the mechanical effects of M, joint replicas with three different strengths were 3D-printed using the scanned point cloud information of the natural joint. An anisotropic direct shear test was conducted to obtain the joint shear parameters in eight directions. The results indicated that the new morphology parameter accurately reflects the anisotropic shear behavior of the joint, and displayed tangential, positive linear, and power relations with shear strength, apparent cohesion, and friction angle, respectively. Furthermore, an index for evaluating the shear failure characteristics, established by using the new morphology parameter, can effectively distinguish the differences between the climbing and shear-off behavior on the joint. The parameter M, which considers the micro-slope distribution, can thus correctly represent the physical and mechanical properties of a joint, and its application is conducive to the precise quantification of joint shear behavior.

中文翻译：

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一种考虑节理面微坡度分布影响的节理形态新参数

摘要 关节面形态的准确描述对于解释其剪切行为是必要的。如果定义的形态参数忽略了接头表面的微坡度分布，则可能难以准确区分剪切行为差异。因此定义了初始爬坡角并用它来表征节理剖面上升段的微坡度分布，并提出了一种计算形态参数M的新方法。参数M体现了各向异性，M的取值为在一个方向上以等间隔在同一关节上选择的所有轮廓线均呈对数正态分布。为了研究 M 的机械效应，使用自然关节的扫描点云信息 3D 打印了具有三种不同强度的关节复制品。进行了各向异性直剪试验以获得八个方向的接头剪切参数。结果表明，新的形态参数准确地反映了接头的各向异性剪切行为，并分别显示出与剪切强度、表观粘聚力和摩擦角的切向、正线性和幂关系。此外，通过使用新的形态参数建立的评估剪切破坏特性的指标可以有效区分接头的攀爬和剪切行为之间的差异。考虑微坡度分布的参数M因此可以正确地表示接头的物理力学性能，其应用有利于接头剪切行为的精确量化。