Geotechnical engineering plays a vital role in mine design and safety. It’s not just a support function — it ensures stability across both open pit and underground operations. As part of a geotechnical study conducted at the Sukari Gold Mine in Egypt — and with guidance from experienced geotechnical engineers on-site — I worked on assessing the stability of crown pillars, which serve as the rock mass separating surface and underground mining levels. The assessment involved: Rock mass classification using the Q-system Analysis of joint conditions, RQD, groundwater, and stress environment Evaluation of safety using stability charts and Factor of Safety calculations Poorly designed crown pillars can lead to hazards such as instability, overbreak, or ore dilution due to unplanned rock mass movement — directly impacting both safety and production efficiency. This experience emphasized the importance of turning geological data into engineering decisions that protect people, equipment, and long-term operations.