Ressalat Tunnel is located along the highway of the same name. It is one of the longest East-West main arteries of the Tehran highway network. This project includes two parallel tunnels each consisting of one long section and one short section with a combined length of 1150 m.

The excavation diameter of each tunnel is 16.5 m and the finished diameter is 13.5 m. Tunnel portals are 16.7 m wide separated 4 m from each other. During construction, the excavation was designed for a single portal with an effective width of 37 m.

The tunnels run beneath one of Tehran's residential and business areas and streets with heavy traffic. The excavation of such a large cavity in Tehran's soft soil for the first time with minimal impact on the structures above was an engineering feat. Since aesthetic was one of the important attributes of the tunnels, pre-cast concrete segments (waffles) were specially designed to be used as a permanent part of the concrete structure supporting the tunnel walls. Replicas of ancient Iranian symbolic images are used at the tunnel portals for adornment9An innovative procedure was adopted to run the tunnel underneath Vali-Asr busy street.

Another challenge was the delicate support of a main gas pipeline in Africa Square, with an operating pressure of 250 psi, and construction of two bridges in Africa Square. A Culvert Bridge was also considered in Nezami Valley using traditional Persian architecture.

Project Details

Location: Tehran, Iran

Length 1150 m (each side)

Width 16.5m (each side)

Number of lanes: 3 each side + 1 emergency lane