Impact of multiscale surface roughness on shear behavior of rock fractures.

Saved in:
Bibliographic Details
Title: Impact of multiscale surface roughness on shear behavior of rock fractures.
Authors: Zou, Liangchao1 (AUTHOR) lzo@kth.se, Mas Ivars, Diego2,3 (AUTHOR), Cvetkovic, Vladimir1 (AUTHOR)
Source: Tunneling & Underground Space Technology. Nov2024, Vol. 153, pN.PAG-N.PAG. 1p.
Subjects: Shear strength, Crystalline rocks, Surface roughness, Stress fractures (Orthopedics), Wavelets (Mathematics)
Abstract: • Multiscale roughness of 3D fracture surface is characterized using wavelet decomposition. • Surface unevenness notably affects the peak shear strength of mated and unfilled fractures. • Surface waviness controls the residual shear strength of mated and unfilled fractures. • Surface unevenness can enhance the fracture dilation and surface degradation within a short shear distance. This study investigates the impact of multiscale surface roughness on shear behaviors of crystalline rock fractures. Employing wavelet decomposition, we analyze the multiscale features of 3D fracture surface roughness and characterize each roughness level using statistical parameters. Using a validated shear simulation model, we simulate the direct shear processes of mated fractures with a realistic fracture surface digitalized from the scanning of a granite sample under various normal stresses and decomposed surface roughness levels. The shear behaviors, including the peak and residual shear strengths, shear-induced normal displacement (shear dilation) and surface degradation of the decomposed fractures are analyzed. The results reveal a significant correlation between shear strengths and the multiple levels of surface roughness. For the first time, we demonstrate the crucial role of 3D multiscale surface roughness in determining fracture shear strengths and find that the surface unevenness notably affects the peak shear strength of unfilled and mated fractures, while the surface waviness controls the residual shear strength. The unevenness also can enhance the fracture dilation and surface degradation within a relatively short shear distance (∼1 mm). The findings offer valuable insights for a better understanding and estimation of the shear behaviors of unfilled and mated crystalline rock fractures in engineering practice. [ABSTRACT FROM AUTHOR]
Copyright of Tunneling & Underground Space Technology is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
Database: Engineering Source
Description
Abstract:• Multiscale roughness of 3D fracture surface is characterized using wavelet decomposition. • Surface unevenness notably affects the peak shear strength of mated and unfilled fractures. • Surface waviness controls the residual shear strength of mated and unfilled fractures. • Surface unevenness can enhance the fracture dilation and surface degradation within a short shear distance. This study investigates the impact of multiscale surface roughness on shear behaviors of crystalline rock fractures. Employing wavelet decomposition, we analyze the multiscale features of 3D fracture surface roughness and characterize each roughness level using statistical parameters. Using a validated shear simulation model, we simulate the direct shear processes of mated fractures with a realistic fracture surface digitalized from the scanning of a granite sample under various normal stresses and decomposed surface roughness levels. The shear behaviors, including the peak and residual shear strengths, shear-induced normal displacement (shear dilation) and surface degradation of the decomposed fractures are analyzed. The results reveal a significant correlation between shear strengths and the multiple levels of surface roughness. For the first time, we demonstrate the crucial role of 3D multiscale surface roughness in determining fracture shear strengths and find that the surface unevenness notably affects the peak shear strength of unfilled and mated fractures, while the surface waviness controls the residual shear strength. The unevenness also can enhance the fracture dilation and surface degradation within a relatively short shear distance (∼1 mm). The findings offer valuable insights for a better understanding and estimation of the shear behaviors of unfilled and mated crystalline rock fractures in engineering practice. [ABSTRACT FROM AUTHOR]
ISSN:08867798
DOI:10.1016/j.tust.2024.105974