Influence of foundation shape and thickness on the performance of rigid rockfall protective structures

Abstract

Rockfall barriers are essential for minimizing the hazard due to rockfall and debris flow. They help to increase the resilience of infrastructure and residential areas in mountainous regions and hence act as protective structures. The present study investigates the response of rigid rockfall barriers against impact, focusing on the influence of foundation geometry and base slab thickness. Finite element simulations were conducted to analyze the behaviour of five distinct foundation configurations: Rockfall Barrier with No Anchor (RBNA), Front Single Anchor (RBFA), Rear Single Anchor (RBRA), Double Anchor (RBDA), and Double-side Circular Anchor (RBDCA). The rockfall impact was considered normal to the barrier to maximise the impact energy. The foundation soil was modelled using the Mohr-Coulomb plasticity model. The reinforced concrete behaviour was incorporated using the Concrete Damaged Plasticity (CDP) model, while the steel reinforcement was represented by the Johnson-Cook model. Results indicate that the RBDA configuration offers superior stability, over other variations. Additionally, increasing the base slab thickness inversely affects both settlement and displacement, enhancing the barrier’s resilience. Cross-comparison reveals that while RBDA provides notable improvements, optimizing base slab thickness in RBNA can achieve comparable or superior performance, contingent upon soil bearing capacity. These findings provide actionable insights for the design and implementation of effective rockfall mitigation systems.