Theoretical investigation on the initiation and propagation behavior of dominant cracks in valley slopes

Abstract

The stability of rock slopes is frequently controlled by the initiation and propagation of inherent dominant cracks. This study systematically investigated these processes in valley slopes by combining fracture-mechanics analysis with transparent soil model tests. An analytical expression for the stress field at the dominant crack tip was derived from the slope stress distribution by superposing the corresponding stress intensity factors (SIFs). The theoretical predictions were then validated against observations from transparent soil model tests. The influences of slope angle (β), crack inclination angle (α), crack position parameter (b), and crack length parameter (h) on crack initiation and propagation were quantified. The results indicated that: (1) cracks at the slope crest tended to propagate in shear mode, and the shear crack initiation angle (θ_s) was approximately 8°. Cracks at the slope toe might propagate in either tensile or shear mode. (2) θ_s at the slope crest increased with β, b, and l, and decreased with α. The maximum change in θ_s induced by the considered parameters was approximately 30°. (3) The tensile crack initiation angle (θ_t) at the slop toe decreased with β, α, and l, while the influence of b was comparatively minor. The maximum change in θ_t caused by individual parameters ranged approximately from 25° to 60°. Predicted crack propagation modes and directions showed good agreement with experimental results. These findings provide theoretical guidance for stability assessments of valley slopes controlled by dominant crack propagation.

Keywords

Valley rock slope / Crack initiation angle / Crack propagation mode / Stress field formula / Fracture mechanics

CRediT authorship contribution statement

Xianlun Leng: Writing - original draft, Validation, Software, Methodology, Investigation, Conceptualization. Chuan Wang: Val-idation, Software, Methodology, Investigation. Chengtang Wang: Writing - review & editing, Methodo logy, Investigation, Conceptu-alization. Zhanrong Zhang: Validation, Investigation. Haibin Wang: Validation, Investigation. Lan Cui: Validation, Investigation. Kun Fang: Writing - review & editing, Validation.

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 research was financially supported by the National Nature Science Foundation of China (Nos. 52379110 and 42207222), and the Key Technologies for Accurate Diagnosis and Intelligent Prevention and Control of Slope Hazards in Open Pit Mines, 181 Major R&D projects of Metallurgical Corporation of China Ltd.

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