Application of AFEP and RWP in Water Hazard Detection for Skip Mining Working Faces

Abstract

In deep coal mining, skip mining techniques are increasingly adopted, yet their discontinuous extraction sequences and unique coal pillar support mechanisms create complex overburden failure patterns. This complexity gives rise to severe multi-source water hazards, including persistent threats from bed-separation water, goaf water accumulation, and structural water ingress. The intricate hydro-geological conditions, characterized by variable resistivity and significant electromagnetic interference, often render single geophysical detection methods inadequate, leading to interpretive ambiguities and potential oversight of critical risks.To address these challenges, this study innovatively proposes and demonstrates an integrated detection methodology that synergistically combines the Audio Frequency Electric Penetration (AFEP) method and the Radio Wave Penetration (RWP) method. The core innovation of this research is the design of a coordinated observation system meticulously tailored to the spatial distribution of coal pillars. Beyond data acquisition, a systematic, graded classification framework was established for the comprehensive analysis and fusion of the dual-method results. Crucially, these classification outcomes directly inform the formulation of targeted and tiered governance recommendations, translating detection data into actionable mitigation strategies.Practical application at the 22213 face yielded highly positive results. The integrated approach successfully delineated the spatial distribution of water-bearing anomalies and their connecting channels with a clarity unattainable by either method alone. This not only significantly enhanced the accuracy and reliability of the hydrological threat assessment but also provided a robust scientific foundation for implementing effective water hazard prevention and control measures, thereby ensuring the safe and efficient extraction of the skip mining face.