Seismic performance of tunnel structures: a case study

In the modern world, the underground tunnels and tunnelling facilities are becoming an integral part of the transportation and environmentally preferred means of providing infrastructure. In view of increasing importance, the current study has been carried out to investigate the seismic performances of tunnel structures assessed by investigating seismic vulnerability of underground tunnels. The paper also evaluates the need for seismic design for a communication (road) tunnel located in Zone V, India, based on physical parameters and structural setting. Source parametric data gathered for the earthquakes during the period from CE 1500 to 2012 have been analysed and reported in this work. The study adopts the secondary data collection methodology (i.e. the information obtained from the secondary sources like newspaper, magazines, and Internet). The study also analyses the spatiotemporal variation in b-value and observed that most severe earthquake is located close to high b-value domains. In the analysis correlation between the magnitude and time interval, reduced variate was observed to be low in the final forecast. The findings from this study indicate that within the project life a maximum magnitude (Mw) of earthquake value 8.6 is likely to occur. Therefore, provision of the seismic coefficient is recommended in this tunnel.