Water–silt composite blasting for tunneling

Abstract

With the rapid urbanization and shortage of energy, the construction of underground projects such as urban rail transit, hydropower stations, and coal mines is a general trend. Dust pollution in a work zone after blasting construction causes serious pneumoconiosis in workers. The reason for the large number of new cases of pneumoconiosis every year is that the research conclusions on dust suppression technology are still inconclusive and controversial and fail to provide construction enterprises with scientific and feasible dust suppression solutions. Therefore, this study aims at reviewing the dust suppression techniques and their influencing factors for blasting construction and highlighting the significant achievements and controversial issues of existing dust suppression technologies. An overview of the mechanism and key factors of the blasthole stemming technique indicates that a combination of multiple stemming materials achieves better stemming performance, and the optimal stemming length of sand, water, and drill cuttings is recommended to be 0.5–0.6, 0.5, and 0.19–0.27 times the blasthole length, respectively. Then, the influencing factors of dust suppression efficiency for various ventilation systems are analyzed. The dust suppression efficiency of the hybrid ventilation system with air curtain generators is the best, while the blowing ventilation system is the worst. Moreover, the technical parameters of different spraying technologies and performance of different spray mediums are discussed, indicating that the application of dust suppressants achieve higher respirable dust suppression efficiency (generally 78–93%). Finally, the performance, suitability, and future development trends of various dust suppression technologies are summarized and discussed, and the recommended countermeasures to achieve the standard requirement of respiratory dust permissible exposure limits are highlighted.