Seepage-heat accumulation characteristics and hydrothermal transport calculation model in mining-induced fractured rock mass: Implications for geothermal water control

Abstract

The aim of this paper is to explore hydrothermal transport in surrounding rocks during deep mining, focusing on the mechanisms and key factors influencing groundwater seepage and heat accumulation disasters. Stress–seepage coupling tests were conducted on fractured rock mass with varying roughness under constant-pressure loading/unloading conditions. Also, a permeability model considering joint roughness coefficient and confining pressure was established. The study further examined the evolution of heat transfer in rough fractured rock mass and variations in convective heat transfer characteristics. The heat transfer process was observed to progress through stages of surge, attenuation, and stabilization. Two calculation models were developed using multivariate linear regression and random forest regression to quantify how different factors influenced water–rock convective heat transfer in mining-induced fractured rock mass. The average correlation coefficient R2 of the proposed models exceeded 0.95. The importance scores of osmotic pressure, inlet water temperature, rock temperature, and permeability were 0.417, 0.296, 0.223, and 0.065, respectively. The flow rate and water–rock temperature difference were determined to be the key factors influencing hydrothermal transport. This study enhanced the understanding of the hydrothermal migration mechanisms in surrounding rocks during mining and provided insights into geothermal water control.

Keywords

• Mine heat hazard
• Fractured rock mass
• Seepage-heat accumulation characteristics
• Hydrothermal transport
• Geothermal water control