The Study of Explosion Impact on Underground Tunnels, Case Study: North of Tehran

On the base of the population areas and sensitive military centers and also developing underground civil projects such as buried tunnels in the north of Tehran such as Metro lines projects and military centers, there is the possibility of military threats due to the air attacks of the enemy countries because of the destructive effects on the urban operations. The penetrate missiles are of the dynamic instability factors that threaten the safety of the tunnels. In this study, by using of the numerical analysis, investigated resistance of the considered tunnel against explosion of bunker buster GBU-28 in the various deeps and finally the minimum distance among explosive cavity and crown of the tunnel that it remained stable in the explosive tensions situations determined about 25m. In the distances lower than 25m both critiques of replacement of crown of tunnel and the breaking point indicated instability of tunnel under load due to explosion.