What emergency ventilation strategies are employed to evacuate smoke and harmful fumes during tunnel incidents?

During tunnel incidents, emergency ventilation strategies are crucial for evacuating smoke and harmful fumes to ensure the safety of tunnel users and responders. These strategies are designed to quickly remove smoke and toxic gases, maintain visibility, and create a safe environment for evacuations and emergency response. Several emergency ventilation strategies are employed in road tunnels, including: 1. Reversing Airflow Direction: One of the primary emergency ventilation strategies involves reversing the airflow direction within the tunnel. By changing the direction of ventilation airflow, smoke and harmful fumes can be pushed away from the incident area and towards the tunnel exits, facilitating the evacuation process. 2. High-Speed Ventilation: Increasing the ventilation system's speed is another effective strategy. This increases the rate at which smoke and fumes are extracted from the tunnel, allowing for rapid clearance of hazardous conditions and improved visibility. 3. Jet Fans Activation: Tunnel jet fans, installed at regular intervals, can be activated during emerge....