Numerical prediction of circular tunnel seismic behaviour using hypoplastic soil constitutive model

Abstract

Numerical simulation of the centrifuge experiment with dynamic loading on a small scale circular tunnel model surrounded by dry Buzzard sand is being presented. Considering soil dynamic behaviour properly, analyses were performed using an advanced hypoplastic constitutive model for sands considering the intergranular strain. The results include: settlement, lining forces time histories and peak acceleration in normalized model depth, were in good agreement with experimental data. Additional numerical modelling have been performed using hardening soil model with small-strain stiffness (HSS) and Mohr–Coulomb criteria (MC), then the results compared in detail with the hypoplastic (HP) model. The finite element predictions of settlement time histories and the internal forces mobilized in the tunnel lining were compared and the results declared that although settlements were underestimated by all models, HP has shown better responses in following the experimental trend. Also, internal forces obtained by the HP model showed smaller reversible variations.