Effects of the tip depth of a pre-existing fracture on surface fault ruptures in cemented clay

Ground deformation due to faulting can cause serious damage to buildings and structures. Much attention has been devoted to understanding fault rupture propagation in uncemented soil. However, the effects of a pre-existing fracture in cemented soil on surface fault ruptures are not fully understood. This paper describes a numerical parametric study to investigate the mechanism of normal fault rupture propagation through cemented clay. Special attention was paid to the effect of the location (or tip depth) of a pre-existing fracture on the mechanism. The numerical model and model parameters adopted were verified through two centrifuge model tests. The results show that a zone of influence consisting of a tensile failure zone and a differential settlement zone was induced by normal faulting in cemented clay both with and without a pre-existing fracture. The width of this zone of influence increased with the tip depth of the pre-existing fracture. The effects of the tip depth of a pre-existing fracture on the width of the zone of influence were more significant when the tip was located at a shallow depth.