The existing Salang Tunnel is the first 2.6km long roadway tunnel in Afghanistan, which was constructed 55 years ago through conventional tunnel construction technique. It is located at an altitude of 3400 m so that the portals and mountains are subjected to severe environmental conditions such as freezing and thawing process. Unfortunately, the tunnel suffered from explosions during the civil war and it was blocked for the few times to traffic during the 1990s due to the huge blasting, which caused heavy damages inside the tunnel. The government of Afghanistan is planning to carry out a major rehabilitation and upgrading the existing Salang Tunnel and associated structures (snow galleries and road pavements). The Salang highway has a major socioeconomic importance for Afghanistan since it crosses over the Hindukush mountain range to connect Afghanistan's northern provinces to the Center, East and South of the country. This paper describes the technical/engineering and the functional assessment of the Salang Tunnel and as well the key technical considerations on works for the repairs, rehabilitation and upgrading of the existing Salang Tunnel.
The existing two-lanes, two way Salang Tunnel is the first 2.6 km long roadway tunnel in Afghanistan, which was built almost 55 years ago by a conventional tunnel construction technique. It is located at an altitude of 3400 m at the Salang Pass in the Hindukush, starting the boundary between Parwan and Baghlan provinces of Afghanistan (Fig. 1). The tunnel portals and mountains are subjected to severe environmental conditions such as freezing and thawing process. Unfortunately, the tunnel suffered from explosions during the civil war and it was blocked for the few times to traffic during the 1990s due to huge blasting, which caused heavy damage in the tunnel. In 2010, it was observed that about 6,000 vehicles passed the Salang Tunnel daily. While the tunnel was originally designed for 1,000 vehicles a day, it is now handling seven to ten thousand vehicles a day.
