# Investigation of Geotechnical Seismic Isolation Systems Based on Recycled Tire Rubber-Sand Mixtures
### Research on Geotechnical Seismic Isolation  
[PERSON] [6] proposed a rubber and sand mixture comprising shredded vehicle tires (RSM) as seismic isolation material. This method, termed geotechnical seismic isolation (GSI), involves placing the mixture beneath the building foundation to mitigate lateral and vertical shaking during earthquakes, as demonstrated through experiments and analyses. [PERSON] and [PERSON] [2] claimed that the most critical parameters of GSI method proposed by [PERSON]'s [7] were the structure's weight and soil layer thickness. They determined that a mixture containing 35% rubber content provided sufficient isolation but noted that higher proportions could induce stability issues in the superstructure. [PERSON] et al. [8] examined the application of rubber-sand mixture (RSM) pads in GSI systems, demonstrating that RSM pads have high seismic energy dissipation capacity and can be an effective method for structural protection. [PERSON] et al. [9] explored the potential that GSI technology propose in rural areas of China, finding that rubber-sand mixtures (RSM) offered limited isolation during minor earthquakes but achieve heightened effectiveness during major seismic events. [PERSON] [10] assessed the seismic performance of a rubber-sand mixture (RSM) isolation layer placed beneath a 10-story reinforced concrete building model, showing that the RSM layer reduced accelerations experienced by the structure by up to 48% during shaking. [PERSON] et al. [11] investigated the impact of rubber-sand mixtures (RSM) on the seismic performance of concrete structures' foundation layers, finding that these mixtures decreased base shear forces by up to 40%, particularly in high-rise buildings. [PERSON] et al. [12] investigated the dynamic properties of soils by mixing granular soils with various proportions of granulated rubber. The results indicated that as the rubber content increased, the shear modulus decreased, while an increase in confining pressure led to an increase in the shear modulus. It was observed that in soil without rubber, the damping ratio increased as confining pressure decreased, whereas soil containing rubber exhibited the opposite behavior. Finally, new relationships were defined for maximum shear modulus (G\({}_{\text{max}}\)) and normalized shear modulus (G/G\({}_{\text{max}}\)) as a function of confining pressure and granulated rubber content that in this study, G represents the shear modulus at a given strain level, while G\({}_{\text{max}}\) denotes the maximum shear modulus at very small strains, corresponding to the elastic behavior of the material before any significant nonlinearity occurs. [PERSON] and [PERSON] [5] analyzed the compressibility, strength, and hydraulic conductivity of shredded waste tires both as a standalone material and mixed with soil, aiming to use it as lightweight fill material. The study concluded that this material holds significant potential to address economic and technical challenges in applications such as road embankments and landfill cover materials. [PERSON] and [PERSON] [13] found that granulated rubber-soil mixtures are effective in reducing vibration under seismic loads due to their high damping capacity. Their study demonstrated that rubber-inclusive mixtures positively affect the shear modulus. [PERSON] and [PERSON] [14] examined the use of waste tires as an additive in soils located in earthquake-prone areas. The study investigated the effects of tire particles in granular and fiber forms, produced through various processing techniques, on dynamic properties. Their findings established that the type of processing technique exerts a considerable influence on dynamic properties based on the rubber material's particle size, aspect ratio, and content. In a study by [PERSON] et al. [15], soil material properties were presented with G/G\({}_{\text{max}}\) and D/D\({}_{\text{max}}\) curves within the scope of seismic design and site seismic response analysis, emphasizing their noteworthiness in numerical analysis methods.