Experimental and Numerical Analysis on the Static and Dynamic Performance of Adhesive Bolts in Various Ground Conditions

This study presents an integrated experimental and numerical investigation into the performance of adhesive bolts in surface and tunnel excavations in mine environments, with a particular focus on static and dynamic loading conditions typical of tropical rock formations. More than 300 experimental pull-out tests were conducted on epoxy and vinyl ester chemical bolts embedded in concrete and hard rock substrates. These tests assessed the influence of bolt length, curing time, and substrate condition on load capacity, failure mode, and bond–slip characteristics. Results revealed that epoxy-based anchors provided superior bond strength in early-age and thermally active conditions, while vinyl ester systems offered improved ductility and post-peak behaviour in fractured rock masses. Numerical modelling using Rocscience RS2 (Phase2 and Unwedge) simulated excavation responses under various support scenarios, evaluating bolt lengths (190 mm, 200 mm, and 250 mm) and spacings (0.5 m to 2.0 m). Tensile failure dominated across simulations, especially at wider spacings, while closely spaced anchors significantly enhanced confinement and stress redistribution. This study bridges the current knowledge gap in quantifying chemical anchor (adhesive bolt) performance under complex subsurface conditions, validating their use for both early-age support and long-term stability. The findings support the integration of resin-grouted bolts into modern support designs, especially in seismically sensitive or hydrothermally variable mining environments.