山区公路既有隧道扩建设计探讨

Discussions on Expansion Design of Existing Tunnel in Mountain Highway

山区公路隧道在改善公路线型、缩短里程、保护生态环境等方面起着重要作用。文章结合内龙隧道扩建设计实例,分析了新建隧道设计和扩建隧道设计的差异,探讨了既有隧道扩建设计中需考虑的重点因素与隧道洞口、结构、防排水设计及岩溶处理方法,为今后类似隧道扩建设计提供参考。

The mountain highway tunnel plays an important role in improving the highway liner type,shortening the mileage,and protecting the ecological environment and so on.Combined with the Neilong Tunnel expan-sion design practices,this article analyzed the differences between new tunnel design and tunnel expansion design,and discussed the key considerations in expansion design of existing tunnel as well as the tunnel entrance,structure,waterproofing and drainage design and karst processing method,thereby providing the reference for the expansion construction design of future similar tunnels.