Three Hinge Buckling Laboratory Experiment and Modelling Simulation

Abstract

Near-surface buckling failure typically occurs in horizontally bedded sedimentary rocks in the presence of high horizontal in situ stresses and it is a concern for quarries and open-pit mining operations. Usually, sudden energy release, similar to rock bursting, is the consequence of this failure. Buckling failure causes many economic and environmental problems. Even though some research has been carried out on the topic, many limitations still exist to develop a suitable buckling stability analysis procedure. The most important limitation is the lack of a specific, accurate and cost-effective method to analyze this mechanism; therefore, presenting a quantitative way to assess buckling stability is necessary. This research's primary objective was to identify the limitations and develop a proper buckling stability analysis procedure. Therefore, an extensive literature review was carried out, and a comprehensive buckling database, including all available geological, geometrical, and mechanical parameters, was collected. This phase also was included a statistical analysis of the collected buckling data to complete the first phase in understanding the problem more quantifiably. In the second phase, experimental studies were conducted that included a methodology and the invention of a novel apparatus that can reproduce a simple three hinge buckling (THB) at the laboratory scale. In the third phase, several THB experiments were conducted using the newly introduced THB test. Digital image correlation (DIC) methods and acoustic emission (AE) technology were utilized along with conventional recording methods to monitor the new THB experiment. These tests' experimental results provided quantifiable data and demonstrated that THB failure depends on the thickness/length ratio and axial confinement. Finally, in the fourth phase, a numerical model, based on the two-dimensional discrete element method (DEM), was used to simulate the THB experiment. The recently developed UDEC Voronoi tessellation micromechanical modelling technique was used to reproduce and validate the experimental data. The results represented a good agreement between the experimental and numerical results. Overall, this study improved the understanding of buckling failure behaviour by developing appropriate applicable experimental tests and numerical modelling. This technique can lead to reproducing more complex field-scale models to conduct comprehensive buckling stability analysis in future.