Seismic performance of rubber-sand mixture as a geotechnical seismic isolation system using shaking table test

Abstract

This paper presents a comprehensive investigation into the seismic performance of structures utilizing Rubber-Sand Mixture (RSM) as a Geotechnical Seismic Isolation (GSI) system. Shaking table tests were conducted to evaluate the effectiveness of the RSM layer in modifying the acceleration response and settlement of structures under dynamic loading. The effectiveness of the RSM layer was found to be influenced by various factors, including the rubber content, depth ratio (the RSM layer to the footing width), and ground compaction. The study considers a wide range of RSM depth ratios (0.1–0.8), providing valuable insights into the optimal design of buildings equipped with RSM. The experimental results demonstrate a significant reduction in acceleration response for low-rise and medium-rise buildings, as well as potential benefits for tall buildings with a large depth ratio. However, increasing the RSM thickness is accompanied by larger settlement, highlighting the need for a balance between reducing acceleration and controlling settlement. There is a limit to the effectiveness of the depth ratio beyond which, the de-amplification and final seismic settlement become less sensitive to changes in RSM layer thickness. The study reveals that the RSM layer exhibits a more pronounced reduction in acceleration response in loose ground conditions compared to denser ground conditions. However, even in denser ground, the inclusion of RSM layers contributes to improved seismic performance to a lesser extent. The findings align with prior studies, emphasizing the potential of RSM layers in mitigating the seismic response of structures. By appropriately incorporating RSM layers and considering site-specific factors, engineers can enhance the resilience of structures, leading to safer and more earthquake-resistant built environments.