Characteristic structures of type 2-arch tunnel is exposed to the air outside of the central wall. It can not expect more than freeze resistance by geothermal, low-temperature phenomena long period of temperature decrease below freezing is becoming than in the past. Central wall of concrete freeze line will reach drainage layer because these low-temperature phenomena. It should be freezed to occur by the water flowing into the tunnel.

• 김낙영(한국도로공사 도로교통연구원 수석연구원, 공박) | Kim, Nag Yung Corresponding Author
• 김홍종(한국도로공사 도로교통연구원 책임연구원, 공박) | Kim, Hong Jong
• 심재원(한국도로공사 도로교통연구원 책임연구원, 공박) | Shim, Jae Won