Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

Currently, the wall friction loss coefficient (0.025) applied to general road tunnels, which is an important factor in the design of ventilation and smoke control systems, is also used for soundproof tunnels. However, because soundproof tunnels have different wall flow characteristics due to the protruding structure of H-shaped steel, it is necessary to study an appropriate wall friction loss coefficient that considers the structural characteristics of soundproof tunnel walls. In this study, to determine the wall friction loss coefficient for a soundproof tunnel with H-shaped steel installed at regular intervals, a calculation formula was derived using a general-purpose computational fluid dynamics (CFD) program applied to a reduced-scale model of a soundproof tunnel. The results were then compared with those from a full-scale soundproof tunnel analysis model. The analysis results for the numerical model with H-shaped steel showed that wind speed had little effect on the wall friction loss coefficient. The coefficient decreased linearly as the installation spacing increased, and increased linearly as the steel height increased. Furthermore, a relationship equation for obtaining the wall friction loss coefficient was developed using a reduced-scale analytical model of a circular pipe containing H-shaped steel. The applicability of the equation was examined by comparing it with the results from the soundproof tunnel model, and consistency between the two was confirmed.