Dynamic centrifuge test of shield tunnels with non-water reacting two-component polymer buffer layer

Abstract

A buffer layer is one of the countermeasures to promote the anti-seismic performance of tunnels. A newly invented non-water reacting two-component polymer (NRTCP) is superior in impermeability and durability. The construction process of the NRTCP is time-saving and labor-saving. In this study, in order to verify the seismic isolation efficiency of the NRTCP around a shield tunnel model, a dynamic centrifuge test with several dynamic input signals was conducted. The seismic responses of shield tunnel models with and without the NRTCP layer were compared. The results show that the bending moments of the tunnel model with an NRTCP layer were lower than those without an NRTCP layer. Thus, this indicates that the NRTCP layer positively reduced the bending moment in the tunnel model. The axial strain in the tunnel model with the NRTCP layer was lower than that without the NRTCP layer. In addition, the frequency contents of the acceleration response of the tunnel models were rarely influenced by the NRTCP layer. These findings demonstrated the positive effects of the NRTCP buffer layer on seismic isolation in shield tunnels.