Effects of interior structure as double deck lanes on seismic performance of segmental linings

The double deck system of road tunnel is of large cross-section. To investigate its characteristics under dynamic action large-scale shaking table tests are performed. Through comparison the seismic performance between a double deck tunnel model and a simple tunnel model, the effects of interior structure on the seismic performance of the segmental linings are investigated. The detailed responses of the refined lining rings and interior structure as double deck lanes can be applied to evaluate the seismic performance of the tunnel system. It is found that the presence of interior structure prevents the cross-sectional deformation but increases dynamic normal earth pressures along the external surface of the segmental linings. Additionally, the presence of interior double deck structure induces adverse effects on the extension/closure of the longitudinal joints in the upper half of the segmental linings. Failure to consider the interior structure would overvalue the cross-sectional deformation of the segmental linings, but underestimate the dynamic normal earth pressure on linings.