Tehran’s Tohid Tunnel built in 2009 is the third longest urban tunnel in the Middle East. It also broke the tunnel construction record and opened in less than 30 months.
However, with less than six years since completion, “traces of exhaustion” emerged as deep cracks have appeared causing water leakage into the tunnel, Tadbir24 news website reported.
The surface water accumulating in the tunnel is drained into ducts along the walls and enters a canal installed between the twin tunnels, from where it flows to the southern part before entering the underground qanats. Despite these measures there is water leakage and wide cracks have emerged, causing concern over the tunnel safety.
Project executive manager Ali Oliaei Nia, says the cracks have appeared on the exterior “10-15cm coating concrete.” The recent closure of the tunnels was to give time to engineers to insulate them as a temporary solution. But engineers blame low quality of concrete as the reason for the cracks.
“The engineers in charge should undertake proper maintenance work and ensure there is no serious threat to motorists using the tunnel,” he said.
Background
Work on the tunnel officially commenced in 2007.
Traffic congestion on Tehran highways and the exigencies of a metropolitan city to connect the main highways, made the Tehran Municipality launch exhaustive studies to tackle the problem. The best alternative was found in the construction of a tunnel, similar to the Resalat short tunnel in the capital. Thus Tohid Tunnel was approved.
The tunnel is equipped with 70 jet fans, 1,064 lights, sophisticated power generators, smart firefighting system, traffic alarms and intercom telephones, closed-circuit TV, traffic signs, thermal sensors, air pollution sensors and other facilities.
Located in the area of Chamran Highway, Tohid Square, Jomhouri Square and Navab Highway it extends 3 km.
