Study of Azadi and Tange-Qir tunnels in Ilam province
Azadi tunnel with a length of 1200 meters, a width of 4.10 meters, and a height of 2.7 meters have two lanes for cars and a sidewalk with a width of 1.2 meters.
Tang Qir tunnel with a length of 137 meters is located on the Ilam-Hamil road, the construction was without excavation and the aim was to prevent the closure of the road and improve safety during a rockfall. The structural system of this tunnel is a reinforced concrete wall and an arch with a height of 950 cm from the pavement and a width of 12 meters. There is an 80-centimeter-wide, 50-centimeter-high walkway on both sides of the tunnel in which water transferring canals have been built beneath it.