Numerical simulation of a single shear scenario in fibreglass rock bolts

This study describes developing and validating a numerical model for a single shear test on 20-tonne fibreglass rock bolts using FLAC3D. For this, some pure single-shearing tests were conducted using a metal guillotine single-shearing apparatus. Following this, a conceptual model, including two rectangular blocks with a width and depth of 100 mm and a height of 200 mm, was created to assess the performance of a single-shear fibreglass rock bolt. The conceptual model was then uploaded to FLAC3D. The numerical model incorporates critical parameters such as block dimensions, grid numbers and node spacing to ensure simulation accuracy. The FLAC3D model closely matched the experimental test results in predicting the bolt's properties, including the elastic transition trough, peak shear force, peak displacement and post-failure response. However, the model failed to predict shear forces at lower displacements. This discrepancy may be due to assuming a near-perfect scenario with minimal system imperfections, leading to higher shear forces at lower displacements due to the absence of imperfections to dampen the shear force transfer. As expected, with the increase in shear forces, the model aligned well with data from the experimental tests.