Potential of mitigating liquefaction in a sandy foundation stabilised with scrap tyres cushion

The resource recovery of waste scrap tyres has attracted growing attention from researchers in geotechnical disaster prevention and mitigation. Unlike previous studies using shredded rubber or processed tyre products, this study pioneers the use of whole scrap tyres as a cushion system, which preserves material integrity with near-zero processing energy while providing dual functions of drainage and confinement. A new method for reinforcing the foundation and mitigating liquefaction using scrap tyres was proposed. Three groups of small shaking table tests were conducted to verify the liquefaction resistance potential of the tyre cushion (TC) under various drainage conditions. The tests demonstrated that the TC is feasible for liquefaction resistance due to its good drainage and deformation coordination performance. Furthermore, a simple method was introduced into the numerical simulation of the tyre unit. A numerical model capable of considering the deformation of the TC and the variation of additional cohesion was established. Numerical simulation results indicated that a certain area within the TC was susceptible to damage induced by liquefaction. Beyond the mechanical performance, an extended sustainability assessment demonstrated that the TC system substantially reduces environmental impacts, lowers repair costs, and aligns with circular-economy policies. The proposed technology therefore offers an integrated and scalable solution for sustainable geotechnical engineering.