Journal of Korean Tunnelling and Underground Space Association ISSN:2233-8292(Print) 2287-4747(Online) 한국터널지하공간학회 논문집

Generally, it has been noted that underground structures have a consistent record of suffering much less damage thansurface facilities during earthquakes; but it is still necessary to illustrate the dynamic response of tunnel structuressubject to earthquake loadings and to provide the appropriate method for the seismic analysis of underground tunnelstructures since many types of underground structures have been and will be constructed in countries situated withinseismic zones. In this study, first, seismic analyses for underground tunnel structures are performed by using quasi-static analysis method and dynamic analysis method. Second, seismic analyses in tunnel portals are performed by usingabove methods. The results of seismic analyses for the tunnel structure show that the tunnel structure conforms toground deformation and that seismic design by using the quasi-static analysis method is more conservative than that byusing the dynamic analysis. The results of the dynamic FEM analysis for the tunnel structure show that the simplified 2-D FEM analysis using a sine wave rather than the 3-D FEM analysis can be adopted for seismic analysis. Finally, theresults of the dynamic FEM analysis in tunnel portals show that the force acting on the lining is largest near to thetunnel portal when an earthquake wave propagates parallel to tunnel axis.