Study on the Electric potential response of coal seam damage under mining Influence: A Case from laboratory to field testing

Abstract

Understanding the electrical potential (EP) response of coal mining process and its corresponding relationship with mining disturbances is of great significance for the safety construction of coal mining. In this paper, laboratory experiments and field tests on stress coal EP response were conducted. According to experimental findings, the EP intensity increases with the increase of stress level, and a sudden increase in EP occurs when local fracture happens. During stress wave loading, the EP exhibits periodic fluctuation characteristics. With the attenuation of stress waves, the EP shows exponential decay characteristics. Near the main fault zone, localized strain features are observed, leading to the generation of anomalous EP regions with densely packed contour lines. As the mining working face continues to advance, the stress gradually increases, the EP signal shows a “step-like” periodic upward trend. Significant variations in EP intensity exist across measuring points, yet the overarching evolution trends remain consistent. The intensity and distribution of the EP signal can reflect the stress state and damage of the mining working surface.