In underground mining, rock pillars are frequently utilized to provide support within the deposit. Many of these pillars, either due to their geometry or the stress field acting upon them, experience inclined loads. Hence, this study aims to develop local models to analyze the impact of inclined loads on the stability of rock pillars.
The models were created using FLAC3D for various types of pillars, and the Hoek & Brown failure criterion was applied, employing equivalent parameters to simulate medium quality rock. Through these models, the influence of inclined loads on pillars and the width-height ratio were examined. The results indicate that pillars exhibit reduced resistance to inclined loads with a shear component, while the strength increases with an increased width-height ratio.
This study focuses on analyzing the rock pillars commonly employed as a support method in underground mining. The primary objective of these structures is to ensure local stability between tunnels or rooms, as well as overall stability of the mine, by preventing excessive displacements of the rock mass in areas affected by mining. According to Montiel et al. 2018, a pillar can be defined as a geotechnical element of rock in-situ located between two or more excavations.
Designing these pillars requires crucial knowledge of their strength under various loading conditions. However, due to the nature of mining operations, these loads can be axial, shear, or fall within an intermediate range between the two. This variation depends on the orientation and geometry of the pillar, as well as the stress field acting upon it, which can change over time as the excavation progresses.
Caving methods are based on fracturing the surrounding rock and mineralized material to a sufficient degree to induce a controlled collapse, enabling the extraction of a large volume of ore. This process involves detaching the rock through explosive means, causing it to fall and subsequently be extracted upon reaching the deposit floor. As minerals are extracted, the stress surrounding the cavity increases, leading to the fracturing and subsequent collapse of the rock. This cycle continues in a domino effect until the extraction is complete.
