تاثير زلزله بر سازه هاي زيرزميني و طراحي نگهداري بر اساس بارهاي ديناميكي

Earthquake effects on underground structures designing and maintenance based on dynamic loads

With population expending and communities development, creating tunnels in large cities has been necessary. Road and subway tunnels construction help to reduce traffic and water tunnels eliminate large cities need to water or in dams built are used. Tunnels like any other structure influence different loads and stresses. In general, loads incurred tunnels including static and dynamic loads that must be considered in their designing. Jiroft water tunnel stability condition is evaluated is evaluated in this paper. The initial stress calculated at first and then based on Kirsch relationships secondary stress caused by static loads in wall and crown of the tunnel calculated. Then, by using of seismic analysis based on Free-field deformation, ground strains caused by earthquakes are possible, has been calculated without considering the interaction between tunnel concrete liner and the rock mass. After strain calculated, by using Closed form solutions simplification method and the Wang and Penzias relationships, seismic forces value, means the axial force and bending moment on the tunnel section, has been calculated with due regard to interaction between tunnel concrete liner and the rock mass. The results of this study indicate that underground structures specially the tunnels stability can be affected by loads from earthquake waves.