Earthquake fault rupture - Shallow foundation interaction in undrained soils: a simplified analytical approach

The interaction between normal or reverse fault ruptures and shallow foundations resting on a homogeneous undrained soil layer is investigated. After performing a thorough set of nonlinear finite element simulations, three simple kinematic mechanisms are proposed to predict the conditions for the fault rupture to be diverted by the foundation. The results obtained by both numerical and analytical approaches are in good agreement, and support the adequacy of the proposed mechanisms. A relationship is established for assessing the minimum foundation bearing load needed for diversion of the fault rupture trace, either normal or reverse. This relationship is proved to be independent of the fault type and dip angle, so that it can be applied easily for engineering applications, even in the absence of specific tectonic information.