Performance assessment of a protection embankment designed for a rockfall-prone slope along lesser Himalayas of Jammu and Kashmir, India

Rockfall is a significant hazard in the Himalayan regions of India, threatening lives and property. Rockfall Protection Embankments (RPE) offer a solution by intercepting falling rocks. This study provides a comprehensive performance assessment of a geosynthetic-reinforced Rockfall Protection Embankment designed for a rockfall-prone slope along National Highway-44 in Jammu and Kashmir, India. This particular segment of the arterial road, located in the lesser Himalayan region, is renowned for its high susceptibility to rockfall events. Slope geometry and material parameters are determined through site and laboratory characterization. These data are then utilized to estimate rockfall impact forces using statistical rockfall trajectory analyses. For the estimated trajectories and impact forces, the RPE is designed following available guidelines and insights from reported real-scale impact studies. The RPE's response to rockfall impacts of varying energies and different impact locations is then investigated using dynamic analyses through the three-dimensional finite element platform, PLAXIS 3D. The results demonstrate that the RPE can effectively withstand not only the estimated site-specific impact energy but also substantially higher energy levels. The presence of geogrid reinforcement efficiently localizes deformations and resulting stresses within the impacted zone, limiting damage to the remaining portion of the RPE. Reinforced RPE sections also exhibit the capability to regain stability after being impacted. Impact location is identified as a critical factor, with the top-third portion posing the greatest risk to the structural integrity of the protection structure. The RPE is 100% effective at preventing rock blocks from reaching highways and is significantly more cost-effective than other measures like catchment ditches and flexible barriers. This study provides valuable insights for the site-specific design and performance of rockfall protection embankments.