Abstract
This paper describes a new method of tunnel ventilation system considering the environment for NAGASAKI / ORANDA-ZAKA TUNNEL. Tunnel length is approximately 2950m with two tube and it is required the environment protection for smoke and noise emission from the tunnel entrance. No place was found for vertical ventilation shaft on the ground surface above tunnel, then new method that is connect the upper and lower way with interconnected drift tube was applied. Compactly designed ventilation fans of φ 3150 impeller diameter and silencers were installed above the driving lanes, and tunnel air velocity is controlled with ventilation system.
