Study on dust pollution law and ventilation optimization of roadway excavation and shotcrete simultaneous operation

The simultaneous operation of heading machine and shotcrete machine often occurs in the process of roadway development. Many dust sources, such as cutting dust and shotcrete dust, increase the complexity of roadway dust pollution. In order to find out the law of dust migration in tunneling and shotcrete operation at the same time, and put forward effective dust control optimization measures, this paper takes a mine roadway as an example, based on Fluent numerical simulation software, the dust migration law is analyzed when the roadway driving operation and the shotcrete operation are carried out separately and when the two operations are carried out simultaneously. Moreover, the orthogonal experiment is used to optimize the ventilation parameters of the working face. Results show that the dust concentration in the roadway decreases gradually from high to low when the single shotcrete operation is on the air inlet side. On the return air side, the dust concentration in the roadway increases first and then decreases. In the single tunneling process, the dust concentration on the return air side is significantly higher than that on the inlet side, and at the 52 m section, the dust concentration basically decreases to less than 100 mg/m3. When tunneling and shotcrete work simultaneously, the dust migration distance increases, and the dust concentration decreases to less than 100 mg/m3 at the section of 55 m. Through an orthogonal experiment, the optimal combination of working ventilation parameters is obtained. This study gives a helpful guidance for dust suppression when two or more dust production processes operate simultaneously.