Investigation of the influence of dynamic loads on the fastening of underground mine workings

In the context of the need to increase the energy resistance of underground fasteners under dynamic influence, the study was aimed at an experimental and analytical assessment of the mechanical behaviour of wooden structures, in particular, panels made of cross-glued wood, under the influence of impulsive loads. The purpose of the study was to establish the efficiency of using wood and cross-glued elements as energy-adaptive materials for fastening mine workings. The research methodology was based on laboratory modelling of explosive and seismic modes using stands and digital systems for fixing deformation parameters, considering normalised geometric conditions and the influence of humidity. The tests were carried out with samples prepared for the typical conditions of mine workings in Ukraine, taking into consideration of the geostructural characteristics of the regions of Dnipropetrovsk, Lviv, and Kirovohrad oblasts. It was recorded that cross-glued panels retained structural integrity after the action of pulses with an amplitude of up to 3.0 megapascals and a duration of 0.2 seconds, demonstrating a higher ability to dissipate energy compared to solid wood. It was found that the specific values of absorbed energy for the panels averaged 280-340 joules, and the residual deformation did not exceed 3.4%, which indicated the ability of the material to withstand repeated loads without loss of load-bearing capacity. The results of the study confirmed the feasibility of including cross-glued wood in the composition of fastening systems with high requirements for energy absorption. The practical significance of the obtained data lies in the possibility of modifying underground structures based on available wooden materials with predicted characteristics of adaptation to dynamic impacts