Investigation of the dynamic behavior of sand-EPS block combination using shaking table experiments

Seismic isolation serves as a means to absorb vibrations, minimizing harm and structural risks arising from intense ground movements that cause significant distortions. An intriguing approach involves the incorporation of novel lightweight and nontraditional materials, such as EPS geofoam, into sandy terrains, thereby enhancing certain soil engineering properties. This investigation encompassed a series of experiments utilizing a laminar box apparatus on a shaking table. Its aim was to appraise the dynamic response of the sand-EPS geofoam amalgamation across diverse loading circumstances and strain thresholds. The study delved into the impact of varying factors, including the proportion of EPS geofoam, layering configurations, and strain intensity on the dynamic conduct of the soil-geofoam amalgam. A subsequent comparison with linear viscoelastic site response substantiated a dependable correlation. The findings divulged that escalating shear strain amplitude induced a decline in the shear modulus of the specimens, while concurrently heightening the damping ratio. In essence, an augmentation in the volume percentage of EPS geofoam nestled between the layers of sandy soil led to a reduction in site amplification-a signifier of heightened system damping tendencies. Furthermore, an increased stratification of EPS geofoam throughout the sandy soil repository culminated in a reduction of damping influences. Consequently, the deposit's behavior more closely resembled that of compacted sand. Thus, a robust deduction can be drawn: for optimal damping outcomes, EPS geofoam should be singularly layered within the sand deposit.