earthquake effect on the tehran's niyayeshtunnel

The effect of earthquake on niayesh tunnel in tehran city is investigated. first, by identifying the soil ofthe area, the amount of stress in the up, wall and bottom of the tunnel was calculated. then, by using the accelerationdata of large earthquakes that occurred in different directions of the tunnel construction, displacement and probablerisk caused by earthquakes using plaxis software in three direct, static, quasi-static and dynamic modes afterdrilling, the tunnel was calculated. on average, this value was 45.6 mm on the surface of the earth. the valuesobtained in the dynamic state show that the movement of surface ground the area is restrained by the tunnel. thenatural frequency for the niayesh tunnel using fourier spectrum calculations is 5.94 hz for the building, whichchanges to 5 hz during an earthquake, and the period of the building is 0.16 seconds and 2 seconds during anearthquake. these results are in applicable agreement with other results obtained in other underground spaces.