Abstract:  Against sloping tunnels with different angles,smoke control effect under key smoke exhaust mode was studied. Taking a three lane tunnel as an example,using FDS,working condition of different slope,one-way and two-way key smoke exhaust mode,and different opening mode of smoke vent were simulated. The change rules of key index,such as smoke spreading distance,visibility and natural supplementary wind speed of tunnel portal were analyzed. Suggestions on smoke control optimization of sloping tunnel under key smoke exhaust mode were made.

Key words: smoke exhausting, slope tunnel, smoke, spreading distance, visibility