Centrifuge modeling of underground tunnels and shallow foundations subjected to reverse fault rupture

Due to the problems and high cost of real-scale experimental studies and on the other hand, the ability of small-scale models in geotechnical centrifuges to establish physical similarity and take into account the real stresses in the model for a correct understanding of deformations and rupture mechanisms, major experimental studies on the phenomenon of surface faulting has been done using by geotechnical centrifuge. In this research, the concept of physical modeling with a geotechnical centrifuge, scale rules, constraints, and sources of error in simulating the interaction of dip‐slip fault with underground tunnels and shallow foundations are investigated. Finally, by minimizing modeling errors, the interaction of reverse fault with underground tunnels, as critical transport infrastructure, and the shallow foundation is simulated. The results showed that in reverse fault propagation in sandy soil when the rupture reaches the surface, its dip angle decreases, and at the ground surface, shear ruptures and tension cracks are created which can damage structures and infrastructures. The presence of the tunnel in the rupture path causes the fault rupture path to change and the fault rupture zone to increase at the ground surface, which can affect the performance of surface structures and buried structures adjacent to the tunnel. In the propagation of reverse fault rupture, the presence of the surface structure on fault outcrop, overburden pressure due to the structure, causes the rupture path to deviate to the right corner of the foundation and the structure to rotate. Besides, on the right side of the foundation, a fault scarp was observed, which was consistent with field observations in previous earthquakes with surface fault rupture.