Evaluation of reverse faulting effects on the mechanical response of tunnel lining using centrifuge tests and numerical analysis

The present study refers to the effects of reverse faulting in dry sand on the mechanical response of a tunnel lining. Seven centrifuge tests (five tests with tunnel and fault rupture and two tests without tunnel and with fault rupture as free field) were performed in this research and finite-element models are utilised to gain further insight into the interaction between reverse faulting and the tunnel. The effects of tunnel location and tunnel rigidity are investigated based on the experimental results. Results show that the tunnel location with respect to the location of the fault tip and the rigidity of the tunnel are important parameters affecting the mechanical response of the tunnel lining. The centrifuge tests, in prototype scale, were simulated numerically using a two-dimensional explicit finite-element model in a plane-strain condition. Good agreement between the numerical analysis and centrifuge test results was obtained, indicating proper numerical modelling. A numerical parametric study was then conducted to investigate the safe zone around the fault region for tunnel construction. Finally, it was concluded that the internal forces in the tunnel lining are highly affected by soil stress redistribution caused by faulting.