Applicable Conditions and Limitations of Industrial Electronic Detonator in Hole-by-hole Initiation

The advancement of industrial electronic detonator technology and growing implementation of hole-by-hole initiation methods have drawn significant interest in open-pit blasting operations owing to their precise timing control, effective vibration mitigation capabilities, and potential for enhanced rock fragmentation. However, in practical engineering applications, especially under particular geological and blasting conditions, hole-by-hole initiation demonstrates some technical constraints that need systematic examination. This study, grounded in field operations at a Qingyuan limestone mine with a 15 m bench height and a 152 mm blast-hole diameter, explores the feasibility of hole-by-hole initiation in challenging scenarios, including large resistance lines, by combining theoretical analysis with field comparative tests. The findings reveal that under these specific conditions, the sequential action of single holes′ in hole-by-hole initiation channels explosive energy predominantly toward lateral free surfaces, resulting in inadequate energy distribution at the toe line. This phenomenon adversely affects rock fragmentation quality and elevates toe zone failure occurrences. The experimental results demonstrate that hole-by-hole initiation generates notably shorter muck pile throw distance compared to row-by-row initiation, accompanied by an approximate 4% decrease in bulking factor and generally diminished throwing performance. Building upon the synergistic mechanism of stress wave propagation and explosive gas expansion, this research provides additional clarification on how row-by-row initiation facilitates comprehensive rock mass displacement through coordinated stress wave interference and gas pressure interaction, thereby demonstrating superior performance in addressing large resistance lines and improving muck pile morphology. The research comprehensively outlines the optimal application scenarios for hole-by-hole initiation, emphasizing its effectiveness in vibration-critical zones and moderately hard rock formations with uniformly distributed joints. Conversely, thick structural planes or projects demanding high material displacement and fragmentation are not suitable. These findings offer both theoretical foundations and practical recommendations for appropriate detonation network selection and precision design across diverse engineering contexts.