Variation characteristics of mine inflow during mining of deep buried coal seams in Shaanxi and Inner Mongolia contiguous area

Variation characteristics of mine inflow are the key for coal mine safety during exploitation of the deep buried coal seams in Shaanxi and Inner Mongolia contiguous area. The characteristics and influence factors(e.g. hydrogeological conditions, roadway tunneling footage and radius of mining goaf) were studied. The results showed that there were three aquifers within range of water flowing fractured zone in Shaanxi and Inner Mongolia contiguous area. Different groundwater inflow affected greatly roadway tunneling and working face mining. Mine water inflow increased with roadway tunneling footage gradually, but unit mine water inflow changed little and the average mine water inflow was 0.008 32 m³/(h·m). When hole water yield and water pressure decreased to less than 5.0 m³/h and 1.0 MPa respectively before extraction, static reserves of roof aquifer were drained completely. Mine water inflow showed stepped gradual increase during the first working face and continuous working face mining. There was a very good linear positive correlation between mine water inflow and radius of goaf. The above research could provide security and scientific basis for other coal mine constructing and working face mining.