Influence of Varying Seismic Hazard and Underlying Soil on the Efficacy of Rocking Foundation for an RC Frame-Shear Wall Building System

Reinforced concrete (RC) frame-shear wall building systems are widely adopted in India due to their high strength and stiffness, making them effective in resisting lateral seismic forces. However, their performance during extreme seismic events has revealed limitations, particularly in terms of structural resilience. Foundation rocking is a novel approach for enhancing the seismic resilience and has caught the eye of several researchers. However, allowing the foundation to rock will result in the increase of displacement caused by rotations at the base of the foundation which may cause permanent settlements depending on the underlying soil properties. This study investigates the potential of foundation rocking as an innovative strategy to enhance the seismic resilience of high-rise RC frame-shear wall buildings. Four varying degrees of foundation rocking that can be allowed without compromising the integrity of the building system were analyzed to ensure structural integrity while improving performance. The seismic behavior was assessed through key parameters, including maximum superstructure displacement, peak moment at the foundation, settlement of underlying soil, self-centering ratio, and tipping over ratio. Results demonstrate that the displacements induced by rocking remain within the permissible limits outlined in Indian standards. Additionally, rocking foundations effectively reduce peak moments during seismic events, thereby lowering the seismic demand on the superstructure. The calculated self-centering and tipping over ratios confirm adequate safety margins for all considered scenarios. Overall, the study concludes that controlled foundation rocking significantly enhances the seismic resilience of RC frame-shear wall systems, offering a promising direction for earthquake-resistant construction in India.