Research progress on installation and maintenance techniques of ventilation ducts in drill-and-blast tunnel...

In China, more than 90% of transportation tunnels are constructed by drill-and-blast method. As the only path for air exchange between the construction period of drill-and-blast method tunnel and the external environment, the ventilation system is the lifeline for tunnel construction personnel. However, due to the lack of attention to the installation and maintenance of ventilation ducts on site, the actual ventilation performance of the ventilation system hardly reaches the designed level. As a result, the working environment at the tunnel face is difficult to meet the design standards, which affects the safety of construction personnel and the construction efficiency. Based on years of practice and research, it has been confirmed that one of the main factors causing the decay of ventilation performance in tunnel construction ventilation systems is air leakage and increased air resistance in ventilation ducts. Through investigating the existing literature on the installation and maintenance techniques of the tunnel construction ventilation system, this review looks back on the connection techniques between ventilation ducts and fans, the suspension techniques for ventilation ducts in the main tunnel, and the techniques for ventilation ducts to pass through the construction trolley, so as to provide certain reference for the maintenance personnel of the tunnel construction ventilation system.