Quantifying and mapping the heterogeneity of rock joint roughness and shear strength for rapid field assessment

Abstract

Rock mass stability is significantly influenced by the heterogeneity of rock joint roughness and shear strength. While modern technology facilitates assessing roughness heterogeneity, evaluating shear strength heterogeneity remains challenging. To address this, this study first captures the morphology of large-scale (1000 mm × 1000 mm) slate and granite joints via 3D laser scanning. Analysis of these surfaces and corresponding push/pull tests on carved specimens revealed a potential correlation between the heterogeneity of roughness and shear strength. A comparative evaluation of five statistical metrics identified information entropy (H_s) as the most robust indicator for quantifying rock joint heterogeneity. Further analysis using H_s reveals that the heterogeneity is anisotropic and, critically, that shear strength heterogeneity is governed not only by roughness heterogeneity but is also significantly influenced by the mean roughness value, normal stress, and intact rock tensile strength. Consequently, a simple comparison of roughness H_s values is insufficient for reliably comparing shear strength heterogeneity. To overcome this limitation, a theoretical framework is developed to explicitly map fundamental roughness statistics (mean and heterogeneity) to shear strength heterogeneity. This framework culminates in a practical workflow that allows for the rapid, field-based assessment of shear strength heterogeneity using readily obtainable rock joint roughness data.

Keywords

Rock joint heterogeneity / Roughness / Shear strength / Information entropy / Push/pull test / Rapid field assessment

CRediT authorship contribution statement

Changshuo Wang: Writing - original draft, Visualization, Resources, Methodology, Investigation, Funding acquisition, For-mal analysis, Data curation. Chen Huang: Writing - original draft, Visualization, Methodology, Investigation, Formal analysis, Data curation. Rui Yong: Resources, Funding acquisition, Formal analy-sis, Data curation, Conceptualization. Guangjian Liu: Validation. Pengju An: Validation, Resources. Zhongjun Ma: Validation. Jibo Qin: Validation, Resources.

Declaration of competing interest

The authors declare that they have no known competing finan-cial interests or personal relationsh ips that could have appeared to influence the work reported in this paper.

Acknowledgments

This study was supported by the National Natural Science Foun-dation of China (Nos. 42422705, 42207175, 42177117 and 42577170), the Ningbo Youth Leading Talent Project (No. 2024QL051), the Chinese Academy of Engineering Science and Technology Strategy Consulting Project (No. 2025-XZ-57), and the Central Government Funding Program for Guiding Local Science and Technology Development (No. 2025ZY01028). We are also sincerely grateful to the editors and anonymous reviewers for their diligent work and insightful comments.

0 Supplementary material

Supplementary material

Supplementary data to this article can be found online at https://doi.org/10.1016/j.ijmst.2025.11.008.

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