基于CFD-DPM方法的沙滩头隧道掌子面粉尘扩散规律研究

Study on the Regularity of Dust Dispersion at the Shatantou Tunnel Face Based on CFD-DPM Method

粉尘是影响隧道施工人员健康和掘进安全的重要因素之一。为获得风速与隧道粉尘扩散规律的关系,以沙滩头隧道为工程背景,提出基于CFD-DPM数值建模方法,并引入DPM碰撞模型,采用ANSYS Fluent构建隧道三维有限元计算模型,对风速分别为9、12、15和18 m/s工况下,隧道内的气流流动、粉尘扩散和呼吸平面粉尘浓度分布规律开展研究。结果显示,隧道内具有两个高风速区和中部低风速区,高浓度粉尘云的移动与风管出口风速呈近似线性相关。在四种风速条件下,粉尘完全扩散出巷道所需时间分别为150 s、110 s、90 s和80 s。根据隧道内通风时间和粉尘浓度关系,通风全过程可分为通风初期、通风中期和通风稳定期,不同风速条件下在隧道呼吸平面上的最高粉尘浓度分别为111.02、93.26、71.24和67.73 mg/m^(3)。现场实测表明,模拟结果与现场实测数据吻合良好。本研究可为沙滩头隧道合理的通风设计以及安全施工提供依据。

Dust is a significant factor affecting the health of tunnel construction workers and the safety of excavation operations.To understand the relationship between wind speed and dust dispersion regularity in tunnels,this study focuses on the Shatantou Tunnel and proposes a numerical modeling method based on CFD-DPM,incorporating a DEM collision model.A 3D finite element model of the tunnel is constructed in ANSYS Fluent to investigate airflow,dust dispersion,and dust concentration distribution at the breathing plane within the tunnel under wind speeds of 9 m/s,12 m/s,15 m/s,and 18 m/s respectively.The results show that the tunnel has two high wind speed zones and a central low wind speed zone.The movement of high-concentration dust clouds is approximately linearly related to the wind speed at the ventilation outlet.The time required for dust to fully disperse from the tunnel under the four wind speed conditions is 150 s,110 s,90 s,and 80 s,respectively.Based on the relationship between ventilation time and dust concentration in the tunnel,the ventilation process can be divided into the initial ventilation period,the mid-ventilation period,and the stable ventilation period.The highest dust concentrations at the breathing plane under different wind speed conditions are 111.02 mg/m^(3),93.26 mg/m^(3),71.24 mg/m^(3),and 67.73 mg/m^(3),respectively.Field testing shows that the measured data align well with the simulation results.This study provides a basis for rational ventilation design and safe construction of the Shatantou Tunnel.