【摘要】 为研究双掘进面施工隧道内游离SiO₂粉尘浓度演化特征与扩散规律,获取通风系统的合理设计参数,以斗篷山隧道为研究背景,利用Ansys-CFD有限元计算流体力学软件离散项模型对双向掘进隧道安装除尘设备前、后粉尘扩散轨迹及不同时间周期内粉尘浓度分布特点进行数值模拟,并对模拟结果与现场实测数据进行对比分析.结果表明:（1）衬砌台车对粉尘的扩散具有明显的阻碍效应,台车两侧游离SiO₂粉尘浓度值出现了明显的分界.（2）单纯压入式通风条件下,部分高浓度游离SiO₂粉尘在非爆破端循环停留时间较长,通风一段时间后少量高浓度的游离SiO₂粉尘穿过台车在非爆破端循环停留形成簇团效应,未进入斜井进行排放.（3）压入式通风设备和除尘系统联合作业后,非爆破端游离SiO₂粉尘浓度趋于0,联合作业900 s后,隧道正洞与斜井内游离SiO₂粉尘浓度基本降至8 mgm³以下,达到规范要求.研究显示,采用离散项模型对双工作面施工隧道内游离SiO₂粉尘浓度演化特征与扩散规律的模拟是可行的.压入式通风设备与除尘系统联合作业条件下游离SiO₂粉尘快速进入斜井进行排放,隧道施工作业区内游离SiO₂粉尘浓度在短时间内大幅下降,通风过程中粉尘运行轨迹几乎不涉及隧道非爆破端,减少了对非爆破端的污染.更多还原

【Abstract】 Take tunnel Doupengshan as the research background,in order to study the evolution characteristics and diffusion rule of free SiO₂ dust concentration in the double heading tunnel,and to obtain reasonable designing parameters of ventilation system,the diffusion path and concentration distribution of dust were simulated in different time periods before and after dust removal equipment was installed by the discrete term model of Ansys-CFD（a FEM computational fluid dynamics software）.Meanwhile,the simulation results were compared with the field measured data.The results indicate that:（1）Lining platform car had a certain obstructive effect on free SiO₂ dust,and there was a clear demarcation of the concentration of free SiO₂ dust on both sides of platform car.（2）Some high concentration free SiO₂ stayed for a relatively long time in non-blast zone,small amount of high concentration free SiO₂ passed through the platform car to form cluster effects in non-blast zone after a period of ventilation and was undischarged by shaft just under forced ventilation.（3）The concentration of free SiO₂ dust approximated to 0 in non-blast zone in the joint operation of forced ventilation and dust removal system,and the concentration of free SiO₂ dust was reduced to less than 8 mgm³in the main tunnel and shaft after 900 s of the joint operation,which met the regulatory standard.The research result shows that:it was feasible to simulate the evolution characteristics and diffusion rule of free SiO₂ dust concentration in the double heading tunnel by the discrete term model.Under the joint operation of forced ventilation and dust removal system the free SiO₂ dust entered the shaft for discharge quickly and the concentration of free SiO₂ dust decreased sharply in construction area within a short period of time,and the diffusion path of dust almost did not reach the non-blast zone which reduces pollution to non-blast zone in tunnel.更多还原