Physical and numerical modeling uncovers the multi-field evolution of roof karst water inrush during coal mining, indicating a three-stage disaster pathway through induced fracture channels.
Key Points
To determine the multi-field coupling evolution mechanism and catastrophic pathway of roof water inrush from karst pipelines during coal seam excavation.
Synthesized fluid–solid coupling similarity materials replicating karst coal measure strata based on the Qinglong Coal Mine engineering prototype.
Conducted integrated three-dimensional physical modeling and fluid–solid coupling numerical simulations to capture roof stress, displacement, pore water pressure, and electrical conductivity during mining advance.
Physical simulation revealed a 54.8 m combined caving and water-conducting fracture zone, a 16.1 mm maximum roof displacement, a peak pore water pressure of 39.79 kPa, and peak conductivity of 87 ppm.
Numerical modeling demonstrated roof plastic zone connectivity with the karst pipeline at 100 m of advance, accompanied by a 2.65 MPa maximum stress increment, 52.80 mm displacement, and 1.86 MPa peak pore water pressure.
Identified the 'karst pipeline—lower-right fracture channel—working face' as the primary inrush route, progressing through stable, accumulation, and water inrush stages.