Abstract: Aerosol injection technology (AIT) is a new type of active drainage technology. Aerosol injection is carried out in an injection hole through a rotating pipe with a high-pressure pump, which plays three major roles including deep three-dimensional drainage, deep pressurization and air-lift precipitation to improve drainage efficiency. Aiming at the effect of air-lift precipitation, a large-scale air-lift model test device has been independently developed, and a series of experimental studies has been carried out on variables such as the lower medium, surrounding medium, air injection pressure, air-lift drainage channel size and air injection depth. The research results show that: 1) The surrounding medium has little effect on the air-lift precipitation depth but has a great impact on the water level drop speed; 2) The air injection pressure is not directly proportional to the maximum air-lift precipitation depth. The maximum air-lift precipitation depth can only be reached when the air injection pressure is well matched with the diameter of the vertical drainage body; 3) When the diameter of the vertical drainage body is constant, the air injection depth determines the maximum precipitation depth and precipitation rate. The research results can guide the implementation of AIT and provide a basis for further study on the air-lift precipitation mechanism of AIT.

Key words: high-pressure air, aerosol, structure decomposition, drainage consolidation, air-lift effect, model test