Numerical modeling of the interaction of normal fault and shallow embedded foundation

The consequences to structures caused by permanent fault displacement have been investigated for dip-slip faulting, but not for the effect of the embedment depth on the interaction between a normal fault rupture and shallow embedded foundation. This study investigated the effect of the embedment depth on the interaction of normal fault rupture and shallow foundation using a numerical model validated with centrifuge experiments. It was found that a gapping interaction mechanism and foundation distress occurred at different foundation positions relative to the fault rupture outcrop for an embedded foundation in comparison with a surface foundation. The extent of this area depended on the combined influences of the foundation position, foundation surcharge, embedment depth, and fault dip angle. The sidewalls of the shallow embedded foundation were observed to act as kinematic constraints and had considerable influence on the rotation, displacement and stressing of the foundations. With regard to the level of rotation and displacement of the embedded foundation, the lateral earth pressure distribution on the footwall sidewall was similar to that of Rankine active earth pressure in a triangular distribution and on the hangingwall sidewall as a parabolic distribution of passive earth pressure. Foundations laid on loose soil exhibited less rotation than those on dense soil because the fault ruptures were absorbed or bifurcated around both sides of the foundation.