为解决由于隧道施工断面大、在开挖过程中产生的粉尘难以通过施工通风排除的问题，对秦岭天台山隧道（双向6车道）施工过程中钻孔、爆破、出渣、喷浆等不同工况下的隧道粉尘质量浓度进行现场实测，并根据现场实测结果，对隧道内各工况施工粉尘分布特性进行数值模拟研究，提出适合于大断面隧道施工的粉尘控制措施。现场测试结果表明，出渣和喷浆工况下，粉尘质量浓度超过规范要求数倍。通过数值模拟得到： 1）靠近掌子面40 m区域内粉尘质量浓度不稳定，下降趋势不明显； 2）在布置风管时，风管末段至掌子面距离建议取为60~80 m，以保证新鲜风以较大的喷射面抵达掌子面； 3）建议采用附壁风筒降尘+车载除尘方案，除尘效率达95%，能有效处理隧道各区域粉尘，且对施工造成的影响小。

The dust produced during construction of large crosssection tunnel cannot be easily exhausted by construction ventilation. Hence, field monitoring is carried out on dust concentration under conditions of drilling, blasting, mucking, spraying, etc.; the dust distribution characteristics under different constructions are numerically simulated according to monitoring data; and the dust control measures for large crosssection tunnel construction are put forward. It is showed that the dust concentrations under mucking and spraying exceed limit much. It is concluded by numerical simulation that: (1) The dust concentration in the area 40 m close to the excavation face is unstable, the downward trend is not obvious. (2) In order to ensure that the fresh air arrives at the excavation face with a larger spray surface, the distance between duct pipe end to excavation face is recommended to be 60 to 80 m when arranging the ventilation pipes. (3) It is recommended to use the wallhung wind pipe dust reduction + vehiclecarried dust removal scheme, whose dust removal efficiency can reach 95%, and which can effectively reduce the dust concentration in various areas of the tunnel, and has little impact on construction.