Upper Bound Finite Element Limit Analysis of the Response of Shallow Foundations Subjected to Dip-Slip Reverse Fault Rupture Outcrop

In this study, the interaction of reverse fault rupture outcrop with rigid strip foundations overlying a sand deposit is examined using the well-established method of upper bound limit analysis in conjunction with the finite element discretization and linear programming technique. The results of the numerical analyses are compared with the experimental works in the literature, and a qualitatively satisfying agreement is observed. The verified numerical approach is then implemented to perform a parametric survey on the interaction of a reverse fault rupture outcrop with a rigid strip footing resting on a granular soil deposit. Accordingly, the influences of several parameters, including the foundation width, the service bearing pressure, the soil shear strength parameters, the fault throw, the dip angle of the fault offset, and the relative distance between the foundation and the fault rupture dislocation, on the rotation rate of strip footing are thoroughly examined and discussed. The findings of the study show that the foundation rotation increases with the increase in the amount of fault throw on the bedrock and along the fault path. In addition, it is observed that increasing the foundation width, surcharge loading, and fault dip angle as well as decreasing the internal friction angle of the soil medium lead to an overall reduction in the angular distortion of the shallow foundation for almost all cases under study. The superb efficiency of the two main mitigation schemes, including the EPS wall and soil-bentonite wall, to divert the mainstream of the fault rupture from the overlying foundation is also depicted and discussed.