Taking river-crossing tunnel of Hangzhou as an example

in this paper

the general rule of safe evacuation under tunnel fire and all factors having influences on it are analyzed

and a method of studying safe evacuation is presented.By setting different fire scenes including the most disadvantageous condition and numerically simulating the movement of fire smoke and personnel evacuation

the curves of available safe egress time（ASET） and the required safe egress time（REST） are obtained for each fire scene in the tunnel.By comparing the two curves

the parameters are obtained for setting the evacuation channels

on the basis of which the tunnel fire control can be reasonably designed.