关键词: 隧道工程, 毗邻隧道, 光环境模拟, 二次污染, 数值模拟

Abstract: Lighting of adjacent tunnels in the tunnel group is significantly different from that of the single tunnel. In order to reduce the traffic accidents caused by the difference of the light intensity at adjacent tunnel entrances during the daytime, sunshade awnings measures were adopted at tunnel entrances to reduce light, and to satisfy the drivers visual characteristics. However, the structure was often closed, and the pollutants in the upstream tunnel portal could easily flow to the downstream tunnel entrance to form “secondary pollution”. Based on the adjacent tunnels, a sunshade with hollowed-out on both sides of the bottom and closed on the top was constructed, and the light simulation analysis software Daylight Visualizer was used to analyze the rule of brightness change and the light reduction effect of sunshade of adjacent tunnels. The three-dimensional turbulence model based on the standard k-ε two-equation and the multi-group diffusion transfer were used as the physical calculation models. Ansys Fluent fluid analysis software was used to simulate the diffusion of pollutants at adjacent tunnel entrances with or without sunshade awnings. The results show that the constructed sunshade (transmittance 30%) can greatly reduce the gap of road illumination between tunnels, and it can better improve the diffusion of pollutants at tunnel portals, compared with the rather closed sunshade shed.

Key words: tunnel engineering, adjacent tunnel, light environment simulation, secondary pollution, numerical simulation