Effects of Seismic Waves on the Segmental Lining of Shiraz Subway Line 2: A Case Study

Shield tunnels are among the most important projects that play an important role in urban development. One of the most important challenges that can affect the stability of urban tunnels is the performance of segments and joints under seismic excitation. This study aims to investigate the effects of longitudinal joints and ring geometry on the behavior of a segmental tunnel lining subjected to dynamic loading, using 3D numerical simulation of Shiraz Subway Line 2 as the reference case. In this regard, joint pattern as well as interaction with the surrounding soil are fully considered to make the analyses results more accurate. In order to evaluate the effect of ring geometry (i.e., distribution of longitudinal joints in a ring) on the performance of a segmental lining, a ground motion (obtained from Bam earthquake data) is applied to the bottom boundary of soil domain, once in the transverse direction and once in the longitudinal direction. Then, according to the obtained results, the lining response against seismic loading is discussed. Finally, a comparison with some of the well-known analytical solutions is made and the noticeable differences are highlighted.