Abstract
Mining kimberlite deposits in Arctic environments presents unique logistical and environmental challenges, particularly due to the reliance on cement for backfilling, which is costly to transport and environmentally damaging. As an alternative, frozen zero-cement backfill has been proposed to enhance shaft stability while reducing ecological impact. This study employs finite element modeling to evaluate the geomechanical performance of backfilling within the Vertical Cutter Mining (VCM) method, focusing on single shaft and multi shaft configurations at three spacings (6, 10, and 14 m). Comparisons between unfilled shafts (Case One) and backfilled shafts (Case Two) reveal that backfilling consistently reduces stress and strain magnitudes, with von Mises stress and volumetric strain lowered by nearly 50% relative to unfilled conditions. The stabilizing effect was most pronounced at the tightest spacing, where unfilled shafts produced stress levels up to 1.5 times higher than the single shaft baseline. Backfilling also altered failure mechanisms, shifting the depth of instability from shallow zones at −213 m in unfilled shafts to depths approaching −400 m across all spacings. These findings demonstrate that backfilling not only restrains deformation but also delays or prevents failure, enabling denser shaft layouts without compromising geomechanical safety. From an operational perspective, systematic backfilling emerges as an essential stabilizing measure, allowing Arctic kimberlite mining to balance ore recovery with excavation stability and environmental responsibility.