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Influence of Natural Wind on Fire Smoke Propagation in 10 km Long Highway Tunnels
(1. State Key Laboratory of Intelligent Geotechnics and Tunnelling，Southwest Jiaotong University，Chengdu 610031;2. School of Civil Engineering, Southwest Jiaotong University, Chengdu 610031)
Abstract To explore the impact of natural wind on fire smoke propagation within a 10 km long highway tunnel, field tests were conducted to study the meteorological environment at the Taihangshang extra-long highway tunnel site and the distribution pattern of natural wind within the tunnel. A 3D fire dynamics model of the Taihangshang tunnel was established, incorporating a smoke exhaust shaft, to analyze fire scenarios in the middle section of the tunnel,which experiences prolonged smoke propagation. The study reveals the temperature distribution characteristics in the tunnel and the rules of smoke propagation under the influence of natural wind. The findings indicate that: (1) The natural wind speed in the Taihangshang tunnel mainly ranges from 0 to 3 m/s, with the main wind direction in the right line matching the traffic direction, having a distribution probability of 56.78% to 69.73%; (2) Opposite-direction natural wind increases the peak temperature between the fire source and the exhaust outlet, inhibiting smoke propagation; (3) Same-direction natural wind drives the smoke towards the downstream zone of the exhaust outlet,enlarging the high-temperature zone. When the same-direction wind speed reaches 2.88 m/s, the downstream space of the exhaust outlet is filled with fire smoke; (4) Natural wind inside the tunnel reduces the smoke exhaust efficiency,with wind speeds that provide a 70% guarantee rate causing a reduction in smoke exhaust efficiency by 27.76% for same-direction wind and 15.59% for opposite-direction wind.
Abstract：
To explore the impact of natural wind on fire smoke propagation within a 10 km long highway tunnel, field tests were conducted to study the meteorological environment at the Taihangshang extra-long highway tunnel site and the distribution pattern of natural wind within the tunnel. A 3D fire dynamics model of the Taihangshang tunnel was established, incorporating a smoke exhaust shaft, to analyze fire scenarios in the middle section of the tunnel,which experiences prolonged smoke propagation. The study reveals the temperature distribution characteristics in the tunnel and the rules of smoke propagation under the influence of natural wind. The findings indicate that: (1) The natural wind speed in the Taihangshang tunnel mainly ranges from 0 to 3 m/s, with the main wind direction in the right line matching the traffic direction, having a distribution probability of 56.78% to 69.73%; (2) Opposite-direction natural wind increases the peak temperature between the fire source and the exhaust outlet, inhibiting smoke propagation; (3) Same-direction natural wind drives the smoke towards the downstream zone of the exhaust outlet,enlarging the high-temperature zone. When the same-direction wind speed reaches 2.88 m/s, the downstream space of the exhaust outlet is filled with fire smoke; (4) Natural wind inside the tunnel reduces the smoke exhaust efficiency,with wind speeds that provide a 70% guarantee rate causing a reduction in smoke exhaust efficiency by 27.76% for same-direction wind and 15.59% for opposite-direction wind.
TAN Yinjun1,
2 WANG Keli1,
2 ZHANG Heng1 etc
.Influence of Natural Wind on Fire Smoke Propagation in 10 km Long Highway Tunnels[J] MODERN TUNNELLING TECHNOLOGY, 2025,V62(1): 103-113
2025, Vol. 62 