The role of constitutive and numerical modelling in seismic design and retrofitting of tunnels

The contribution examines the seismic behaviour of tunnels and proposes strategies for designing new structures and evaluating existing ones. During the design stage, accurately estimating the inertial response of the surrounding soil is crucial, which necessitates the selection of an appropriate constitutive model. In certain scenarios, conducting fully-coupled dynamic analyses becomes essential to capture significant soilstructure interaction effects. These analyses are also particularly valuable for assessing the seismic performance of existing structures, especially when dealing with damaged or inadequately thick linings, or flexible linings at the invert arch, as discussed with reference to the case-history of the TT10 tunnel at CERN.