The Yamanote Tunnel of the Metropolitan Expressway is an approximately 18.2 km long urban tunnel with heavy traffic and multiple branching junctions within it. Due to its characteristics, special ventilation operations are required not only for Visibility and CO ventilation during normal conditions but also for exhaust gas extraction at the tunnel exit, heat management within the tunnel, and condensation prevention on side mirrors during merging. In particular, condensation on side mirrors that occurs during merging at entry points directly affects driving safety. Therefore, the ventilation operations were reviewed to better suppress condensation during merging. In this review, a new and highly reproducible model was developed and employed, treating the inner and outer circles not as separate tunnels, but as a single integrated tunnel connected via the center ramp. This paper reports on the revised condensation countermeasure operations using the newly developed ventilation calculation model. It also presents the verification results based on actual tunnel measurements.
HATANO et al. (Wed,) studied this question.