An Advanced Shear Strength Criterion for Rock Discontinuities Considering Size and Low Shear Rate

Applied Sciences

Zhifa Zhan¹  Chonglang Wang²  Bowen Zheng³  Shengwen Qi³  Guangming Luo³  Xiaolin Huang³  Songfeng Guo³ 

[1] China Highway Engineering Consulting Corporation, Beijing 100089, China;Department of Civil & Mineral Engineering, University of Toronto, Toronto, ON M5S 1A4, Canada;Key Laboratory of Shale Gas and Geoengineering, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;

关键词: rock mass engineering geomechanics;    rock discontinuities;    shear loading;    strength assessment;    size and shear rate effects;    qualitative characterization;   

DOI  :  10.3390/app10124095

来源: DOAJ

【 摘 要 】

The shear strength of the rock discontinuities under different shear rates is of great importance to evaluate the stability of rock mass engineering, which is remarkably influenced by the size effects induced by both the length and the undulated amplitude of discontinuities. An advanced shear strength criterion taking into account the size and the shear rate simultaneously was proposed. There is an advantage of the dimension unity in terms of the new shear strength criterion in comparison to previous related empirical equations. Additionally, it can be degraded into the International Society for Rock Mechanics (ISRM)-suggested Barton shear strength empirical equation on the peak shear strength of the rock discontinuities. Then, based on a new dynamic direct shear testing device on rock joints, the granite discontinuities with various lengths (200 mm to 1000 mm) and undulated amplitudes (3 mm to 23 mm) were designed to conduct direct shear tests under different low shear rates (0 mm/s to 1 mm/s) to verify the involved empirical equations. It was found that the results predicted by the new shear strength criterion agreed well with the experimental results. It was proved that the new shear strength criterion had a better applicability to characterize the shear strength of the rock discontinuities.

【 授权许可】

Unknown