Assessment of damages in fault rupture–shallow foundation interaction due to the existence of underground structures

Abstract

Permanent ground deformations induced by fault movements can be damaging to engineering structures built on or near active faults. Most experimental and numerical studies have so far confirmed the fact that the presence of a tunnel in the vicinity of an active fault can change the zone of large deformations on the ground surface. This paper investigates the effect of tunnel existence on the interaction between a reverse fault and a shallow foundation using the finite element method. This paper also analyzes the manner in which a foundation in faulting zones responds to various parameters such as foundation position, tunnel depth and diameter, and the position of the tunnel relative to the rupture path in free-field condition. The mechanical response of the tunnel lining is also examined. The results show that the existence of a tunnel, in some cases, can increase the foundation rotation. Varying the tunnel diameter did not cause any significant changes in the general pattern of failure and the location of shear planes near the tunnel. However, a tunnel with a larger diameter causes the rupture to deviate and propagate in a wider area of the soil layer. It was found that increasing the tunnel depth extends a branch of the rupture path towards the footwall and expands the shear zone on a wider area. In the end, this paper examines the effectiveness of expanded polystyrene sheet (EPS) walls in mitigating the surface fault rupture and reducing the foundation rotation.