扬州瘦西湖隧道为穿过国家5A级风景名胜区的单管双层隧道，为了解决洞口环保问题，采用SES对隧道内通风量和污染物浓度进行了模拟计算，结合洞口污染物扩散范围和环境敏感点分布情况，确定了上下层隧道均采用竖井排出式的纵向通风方式； 针对烟气沉降速度快的特点，优化了横断面布置，在盾构段和部分明挖段设置排烟道，采用重点排烟的方式，人员安全可用疏散时间提高了1倍，并且在疏散楼梯间采用了上下层分别设置加压送风机的方式，确保了烟气不会进入非事故隧道，极大地提高了人员的安全性。

Shouxihu tunnel in Yangzhou, which crosses underneath the Grade 5A scenic area, is a singlebore doubledeck tunnel. In the paper, SES is applied to simulate the ventilation air volume and pollutant concentration inside the tunnel, so as to protect the environment near the tunnel portals. Longitudinal ventilation is determined to be applied for both the upper tunnel tube and the lower tunnel tube, considering the range of the pollutant dispersion and the environmental sensitive points near the tunnel portals. The layout of the crosssection of the tunnel is optimized and smoke passages are arranged in the shieldbored tunnel section and part of the cutandcover tunnel section, considering the fast sediment of the smokes. The key smoke exhaust mode adopted doubles the available safe evacuation time. Forced draught blowers are applied to the emergency staircases of the upper tunnel tube and the lower tunnel tube respectively, which ensures that no smoke can enter the nonaccident tunnel tube and in turn improves the safety of the passengers significantly.