TITLE:
UAV-Based Geometry-Controlled Bench Blasting in a Limestone Quarry in Western Senegal: A Case Study on Specific Charge, Drilling Effort and Floor Quality
AUTHORS:
Bocar Sy, Jean Antoine Diouf, Souleymane Niang, Ibrahima Dia, Souleye Sene
KEYWORDS:
UAV Photogrammetry, Digital Terrain Model (DTM), Geometry-Controlled Blasting, Bench Blasting, Specific Charge, Fragmentation Analysis, Quarry Floor Quality, Mining 4.0.
JOURNAL NAME:
Open Journal of Applied Sciences,
Vol.16 No.1,
January
22,
2026
ABSTRACT: Efficient bench blasting in quarries depends on how well drilling patterns account for actual bench geometry, yet design templates are still often repeated with limited geometric feedback. This paper presents a quantitative case study from a limestone quarry in western Senegal, where a UAV and DTM-based digital workflow is used to design and evaluate geometry-controlled bench blasting. GNSS-controlled UAV photogrammetry is used to generate a pre-blast as-built digital terrain model (DTM), from which hole positions, depths and charge distributions are derived. Post-blast UAV surveys provide updated DTMs and orthomosaics to compute differential DTMs (ΔDTM), slope classes and fragmentation metrics. One blast designed from the as-built DTM is benchmarked against four legacy blasts fired on the same bench. The geometry-controlled blast delivers the largest blasted volume (5545.6 m3) at the lowest specific charge (q ≈ 374 g·m−3), while eliminating about 20.9 m of unnecessary drilling (≈6% of planned footage) relative to the design. ΔDTM and slope maps indicate that about 72% of the bench floor is both flat (slope ≤ 3%) and within a ±0.15 m elevation tolerance, reducing the extent of areas requiring dozing or geometric correction. Image-based particle sizing, combined with Rosin-Rammler modelling, predicts that 96.8% of the rock mass is finer than the 800 mm top-size specified by the client, providing a model-based estimate of near-compliance with the ≥ 97% contractual criterion. The results, based on descriptive statistics from one optimized blast and four legacy blasts, demonstrate that UAV-based geometry control can reduce specific charge and drilling effort while improving floor quality, and that the workflow is directly transferable to other quarries seeking spatially explicit indicators to support blast optimisation.