“the Influence of Tunnels on the Nearby Buildings under Seismic Loadings Conditions”, Case Study: Shiraz Underground-iran

One of the most important factors affecting the design of the structures, is the impact of the earthquake loadings on the forces and the design displacements. Nevertheless, the influences of the near structures on the existing buildings, that sometimes can cause great changes in forces and displacements, can never be forgotten. Thus, the induced displacement in the adjacent buildings of a newly constructed underground tunnel, have been investigated in this study. Having the results of the study, it can be evaluated, whether the amount of variations in forces and displacements are in the allowable ranges, and what measures are needed to save the structures in case of having excess changes in these parameters. In this paper, the site characteristics of an underground tunnels are first investigated. Then the excavation of the tunnel is modeled, while the adjacent structures are taking into account. Finally, the impact of the excavation on the adjacent structures under different earthquake loadings are studied and investigated. The corrected accelerograms of the Naghan and El-Centro earthquakes have been used for seismic analyses and a one and two stories buildings have been modeled as the adjacent buildings. In this study since the impact of the tunnels excavations on adjacent buildings under seismic conditions are only concentrated, the radial deformation of the surrounding soils have been neglected. Key word: Tunnel, excavation ,Case study, Earthquake.