Mine water disaster prevention status abroad

Currently, the main use of active protection of foreign law, which uses the ground vertical drilling,ceramic ball dewatering submersible pumps specially aquifer. In order to meet pre-dewatering method, foreign production of high-lift (up to 1000m), a large displacement (up to 5000m3 / h), high power (2000kW) submersible pumps, dewatering project has been its gradual introduction of computer control.
Foreign plugging closure method also has great development, the construction of underground curtain method more and more attention, the Soviet Union that curtain dewatering the future directions of research work. At present, some countries use trenching machine in a loose layer construction curtain; excavation, Wall, slag routine, and is currently plugging closure of foreign advanced technology. But now, no foreign karst formations in the construction of large curtain instance. To take full advantage impermeable layer thickness,frac sand reducing the displacement of foreign impermeable layer being impermeable mechanism of water inrush relationship with fissures, operating under high pressure water inrush mechanism and impermeable layer stability and critical hydraulic resistance combined effects were studied. There are statistical methods currently forecasting methods, catastrophe theory methods and field tests, such as  Hydraulic fracturing  method. Geophysical methods have certain development. Such as Germany, Britain and the United States of seam seismic exploration coal thickness greater than the gap between the faults, and the use of digital seismographs detect underground rock stress distribution; Soviet Union ahead of the hole using radio waves studied karst water bursting with prevention .