关键词: 隧道, 竖井, 烟囱效应, 极限高度, 数值模拟

Abstract: In order to study the effect of the change in the cross-section size of the shaft on the ultimate height of the tunnel chimney effect when a tunnel fire occurs, FDS was used to carry out numerical simulations of tunnel fires in 6 different cross-section sizes when the cross-section shape of the shaft is square.The change of flue gas velocity with time in different positions was analyzed. It is found that there is a limit height for the shaft chimney effect, and it increases with the shaft section size.According to the simulation data, a function expression was obtained and verified by simulation. It can be used to estimate the limit height of the shaft chimney effect when the shaft side length is not less than 0.4 m, but not greater than 3.0 m.

Key words: tunnel; shaft, chimney effect, limit height, numerical simulation