Overview of Inrush Patterns and Rheological Properties of Water-Sand Mining Under Pore Aquifer in China Coalmines

Pore aquifer water is one of the major hazards in China’s coalmines, causing severe pit flooding and human casualties. This article analyses the two types of water conduits, pre-existing and man-made, that are culpable to water-sand inrush when mining undertakes in pore aquifers. It also describes four patterns of inrush mechanisms: 1) water-sand inrush when mining-caused caving zone and water-conductive fissures channelling pore aquifer through pre-existing conduits, such as water-conductive faults;2) water-sand inrush when mining-caused water-conductive fissures channelling pore aquifer; 3) water-sand inrush when mining-caused caving zone channelling pore aquifer; 4) when mining undertakes in steeply inclined coal seam, the water-resistant coal pillar caves and leads to water-sand inrush. This article has also studied the effect of the particles size distribution of pore aquifer on the rheological properties of water-sand by permeation tests. The purpose of this review is to concisely summarize and provide references for countries confronting similar problems and to facilitate international discussions on pore water control.