Reducing shallow foundation rotation due to reverse faulting using predefined shear planes

Abstract

Permanent ground displacement due to faulting during strong earthquakes threatens stability of civil structures. To protect surface foundations from faulting, several mitigation techniques have been developed. Due to limitations of earlier mitigation strategies for unidentified reverse faulting conditions, this research presents a novel mitigation system, including installing sliders beneath the wings of a V-shaped concrete element, to reduce footing rotation. To evaluate the effectiveness of the suggested mitigation strategy, concrete strength tests, a physical centrifuge test and a comprehensive numerical study for different fault locations and dip angles were conducted for the first time. Results demonstrated that the placement of the sliders beneath the V-shaped wings had a significant effect on dissipating the fault dislocation. Compared to the previous mitigation techniques, the proposed system decreased the foundation rotation from a high value (11o) to a low value (3.2o) for the worst-case scenarios. Furthermore, the friction coefficients among sliders and concrete, the concrete wing inclination angle, length, and thickness were critical parameters to design the optimum proposed system. On the other hand, soil layer thickness and relative density did not significantly affect the footing rotation.