As a modern city’s “fourth dimension space”, UTLT is a typical narrow and confined underground space. Due to the special structural position and the curvature of the tunnel, the hot smoke in the fire field can easily form a “smoke turning circle” phenomenon, which greatly reduces environmental visibility and threatens people escape quickly. This article takes a UTLT small radius tunnel as an example to investigate the relationship between the curvature of the tunnel and the visibility of the fire near the fire source. Firstly, using Pyrosim to simulate the change of visibility in different curvatures of fire field, and using SPSS to carry out multiple regression analysis on numerical simulation data, summarizing the prediction model of the impact of small radius UTLT tunnel curvature on the visibility near the fire source. Finally, regression model analysis and test show that the curvature is negatively correlated with the visibility of the tunnel and the prediction model is feasible. The research results can provide theoretical guidance for the design of UTLT-type small-radius circulation smoke evacuation and rapid evacuation of personnel, and provide a reference for similar curve tunnel curvature design and smoke control measures.
The Prediction Model of Influence of Small Radius UTLT Curvature on Fire Site Visibility Based on Pyrosim Multiple Regression Analysis