Research on the influence of axial deck media on damage and stress field distribution characteristics of glauconite

Abstract

The type of axial decking medium significantly influences the efficiency of rock blasting fragmentation, the distribution of the stress field, and the energy transmitted into the rock. This study conducted experiments on glauconite samples utilizing a passive confining pressure device outfitted with four distinct axial decking media charge structures to indicate the rock-breaking mechanism associated with various axial decking media. In conjunction with box counting dimension and fractal dimension theories, computer tomography (CT) scanning and 3D model reconstruction techniques are utilized to visualize the spatial distribution and morphology of explosion-induced cracks. This approach also facilitates a quantitative analysis of the rock damage incurred by the explosions. The results indicated that liquid (water) deck medium charges result in the most substantial rock damage, followed by solid (rock powder), solid (sand), and gas (air) deck medium charges, respectively. The maximum rock damage recorded with water deck medium charges is 0.826, whereas the minimum is 0.778 for air deck medium charges. Then, LS-DYNA numerical simulation software is employed to develop rock blasting models with varying deck media charges, capturing the dynamic evolution of rock damage. The numerical outcomes confirm the laboratory ones and illustrate how different decking media impact the distribution of the explosive stress field and energy transfer efficiency. When employing a liquid (water) axial decking medium, the rock demonstrates the greatest internal energy input and the swiftest rate of energy transfer, with the internal energy input being 1.12 times and 1.68 times that of solid and gas media, respectively. These insights offer valuable theoretical support for designing and optimizing axial decking charge structures in field applications.