Fracture characteristics and fracture interface buckling mechanism of cantilever rock mass under non-uniformly distributed load

Abstract

This study examined non-uniform loading in goaf cantilever rock masses via testing, modeling, and mechanical analysis to solve instantaneous fracture and section buckling from mining abutment pressure. The study investigates the non-uniform load gradient effect on fracture characteristics, including load characteristics, fracture location, fracture distribution, and section roughness. A digital model for fracture interface buckling analysis was developed, elucidating the influence of non-uniform load gradients on Fracture Interface Curvature (FIC), Buckling Rate of Change (BRC), and Buckling Domain Field (BDF). The findings reveal that nonlinear tensile stress concentration and abrupt tensile-compressive-shear strain mutations under non-uniform loading are fundamental mechanisms driving fracture path buckling in cantilever rock mass structures. The buckling process of rock mass under non-uniform load can be divided into two stages: low load gradient and high gradient load. In the stage of low gradient load, the buckling behavior is mainly reflected in the compression-shear fracture of the edge. In the stage of high gradient load, a buckling band along the loading direction is gradually formed in the rock mass. These buckling principles establish a theoretical basis for accurately characterizing bearing fractures, fracture interface instability, and vibration sources within overlying cantilever rock masses in goaf.

Keywords

Cantilever rock mass / Non-uniformly distributed load / Fracture characteristics / Buckling fracture / Digital model

CRediT authorship contribution statement

Wenlong Shen: Writing – original draft, Funding acquisition, Conceptualization. Ziqiang Chen: Writing – review & editing, Formal analysis, Data curation, Conceptualization. Meng Wang: Writing – original draft, Visualization, Supervision, Data curation, Conceptualization. Jianbiao Bai: Visualization, Project administration. Zhengyuan Qin: Data curation. Tongqiang Xiao: Methodology. Ningkang Meng: Visualization, Methodology, Data curation. Juntao Liu: Resources. Yan Gai: Data curation. Hua Nan: Methodology.

Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

The authors are grateful for the financial support provided by the National Natural Science Foundation of China (No. 52274077), the Natural Science Foundation of Henan (No. 242300421072), the Youth Elite Teachers Cultivation Program for Higher Education Institutions in Henan Province (No. 2024GGJS036), the Funds for Distinguished Young Scholars of Henan Polytechnic University (No. J2023-3), and the Young Core Teacher Funding Scheme of Henan Polytechnic University (No. 2023XQG-09).

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