Ventilation method for ensuring positive pressure of lower evacuation channel of long and large shield tunnel

Abstract

The invention discloses a ventilation method for ensuring positive pressure of a lower evacuation channel of a long and large shield tunnel, and relates to the technical field of highway tunnels. Theventilation method comprises the following operation steps that a shield tunnel lane lower layer is used as the longitudinal evacuation channel; safe escape exits and escape exit cover plates are formed in the shield tunnel section lane layer at intervals according to a certain distance, and is connected with a lane lower layer space through sliding stairways; the longitudinal evacuation channel is provided with front rooms corresponding to the sliding stairways; axial flow fans are arranged at the two ends of the shield tunnel lane lower layer to conduct pressurizing and wind supplying on thelongitudinal evacuation channel, and the axial flow fans are arranged to conduct pressurizing and wind supplying on each front room; and when a fire accident happens, downstream personnel of fire points of the lane layer open the escape exit cover plates to evacuate people to pass through the sliding stairways to the front rooms through the safe escape exits, and the relevant axial flow fans arestarted to conduct pressurizing and wing supplying on the longitudinal evacuation channel and the front rooms of the longitudinal evacuation channel. The fact that flue gas invades the evacuation channel can be effectively prevented, an effective ensuring role for safety evacuation of driver and conductor in the tunnel during the fire can be played, and meanwhile, an active role in fire rescue isplayed.

Description

technical field [0001] The invention relates to the technical field of municipal and highway tunnels; in particular, it relates to a ventilation method for ensuring positive pressure in the lower evacuation passage of a long shield tunnel. Background technique [0002] Commonly used evacuation methods for municipal and highway tunnels are: ①Evacuation by setting up horizontal communication passages; ②Evacuation by setting up service tunnels; ③Longitudinal evacuation by using the lower layer of the carriageway. Combinations of the above evacuation methods are also possible. The choice of evacuation method should be considered from investment, construction risk, evacuation effect and other aspects. The evacuation method of setting up service tunnels and horizontal communication channels is much higher in civil construction investment than longitudinal evacuation, and setting up horizontal communication channels increases the construction risk of shield tunneling. For long sh...

AI Technical Summary

Problems solved by technology

[0005] The pressurized air supply scheme ① is suitable for shorter tunnels; the pressurized air supply scheme ② is suitable for long tunnels. When the escape hatch cover plate at the negative pressure end of the jet fan is opened, there will be problems at the mouth of the safe escape opening that cannot meet the wind speed or wind pressure. In the case of high pressure, it cannot be completely guaranteed that the smoke will not invade the evacuation channel

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