Technical Challenges During Construction of Alborz Service Tunnel, Iran

The Tehran Shomal Motorway project is one the major infrastructure projects currently ongoing in Iran. The line will connect the capital of Iran, Tehran with the Caspian Sea. The traffic volume is very high and the conditions of the actual roads, especially in the winter and holiday times are dangerous. The Alborz tunnel system, with the actual ongoing excavation of its service tunnel, is the outstanding lot of the Tehran Shomal Motorway project. The project is facing severe and adverse geological conditions like various dangerous gases, water and material inrush and blocked TBM. Depending on the conditions at the remaining length the breakthrough is anticipated by early 2009.