# Investigation of Geotechnical Seismic Isolation Systems Based on Recycled Tire Rubber-Sand Mixtures
### Research on Geotechnical Seismic Isolation
[31] conducted numerical and experimental analyses to determine an appropriate geometric scaling coefficient for small-scale shaking table tests. The seismic behavior of mid-rise reinforced concrete buildings on silty sand soil was modeled using the 2D finite element method. The results indicated that an appropriately selected scale coefficient could represent real field conditions with sufficient accuracy. Despite extensive research on geotechnical seismic isolation (GSI) methods, significant knowledge gaps remain regarding soil-structure interaction and the dynamic behavior of different materials. [PERSON] [32] provides a fundamental understanding of soil properties, water movement in soil, and stress-strain relationships, serving as a crucial reference for comprehending the mechanical properties of seismic isolation materials. Similarly, [PERSON] [33] offers an in-depth analysis of soil-structure interaction under dynamic loads, providing critical insights for integrating GSI systems into engineering design. Meanwhile, [PERSON], [PERSON] and [PERSON] [34] explores the theoretical foundations and practical applications of seismic isolation systems, making it an essential guide for understanding the impact of GSI methods on structural safety. While these sources are not directly used in experimental studies, they are of immense importance in understanding geotechnical seismic isolation and dynamic soil behavior. Despite the extensive research conducted on geotechnical seismic isolation (GSI) methods, significant gaps remain in our understanding of the dynamic behavior of rubber-sand mixtures (RSM) under varying confining pressures and earthquake excitations. Previous studies, such as those by [PERSON] [6] and [PERSON] [2], have demonstrated the feasibility of RSM in seismic isolation but have primarily focused on empirical approaches and numerical simulations without extensive experimental validation. Similarly, [PERSON] [12] investigated the influence of rubber inclusion on shear modulus and damping ratio but did not address its implications for seismic isolation efficiency across different site conditions. This study fills this research gap by integrating both numerical and experimental analyses to evaluate the effectiveness of RSM layers as seismic isolators. Unlike previous works, which often assume fixed dynamic properties, this study incorporates the strain-dependent variations in the shear modulus and damping ratio, ensuring a more realistic representation of soil behavior under seismic loading. Furthermore, this research expands upon the work of [PERSON] [8] by systematically analyzing the impact of isolation layer thickness, granular rubber content, and confining pressure on seismic response. The findings provide a deeper insight into the trade-offs between isolation performance and material stability, an aspect that has been underexplored in earlier studies. This paper is structured into four sections to guide readers through the study. Section 1 introduces the background, objectives, and significance of the research. Section 2 outlines the materials and methods employed, including the numerical modeling techniques and parametric analyses conducted. Section 3 presents the results and discussions, focusing on the seismic performance of granular rubber-sand mixtures under various conditions. Lastly, Section 4 provides the conclusions and recommendations, emphasizing the practical applications and sustainability of the proposed isolation system.