Abstract To overcome the drawbacks of the existing two-dimensional (2D) roughness parameters, this paper proposes two parameters to characterise the roughness of rock joints. One is used to represent the local features of the joint profiles, and the other is used to characterise the overall features. The proposed local 2D parameter θ2d can provide an alternative approach and facilitate the characterisation of the roughness of the joint rock surface when a three-dimensional measuring apparatus is unavailable. This parameter is calculated using 10 standard joint roughness coefficient (JRC) profiles, and the value of θ2d does not increase monotonically with an increase in the JRC. The results suggest that θ2d can reflect the local waviness but fails to describe the overall features of the profiles. Another parameter, h1, is introduced to consider the overall features of the profiles. A new equation for the JRC is derived by combining the small- and large-scale roughness parameters. Predictions based on the new equation are compared with the experimental data, and the results indicate the applicability of the new equation.

中文翻译：

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两种不同尺度下岩石节理的修正二维粗糙度参数及其与 JRC 的相关性

摘要 为了克服现有二维（2D）粗糙度参数的不足，本文提出了两个参数来表征岩石节理的粗糙度。一个用于表示关节轮廓的局部特征，另一个用于表征整体特征。当三维测量设备不可用时，所提出的局部二维参数 θ2d 可以提供一种替代方法，并有助于表征节理岩石表面的粗糙度。该参数是使用 10 个标准接头粗糙度系数 (JRC) 轮廓计算得出的，θ2d 的值不会随着 JRC 的增加而单调增加。结果表明，θ2d 可以反映局部波纹，但不能描述轮廓的整体特征。另一个参数，h1，引入是为了考虑轮廓的整体特征。通过结合小尺度和大尺度粗糙度参数，推导出 JRC 的新方程。将基于新方程的预测与实验数据进行了比较，结果表明了新方程的适用性。