The study includes the dynamic characterization of clayey soil blended with nano-SiO2 and fly ash under cyclic loading at high strain. The percentages of nano-SiO2 varied between (0.5-7)%, and fly ash varied between (10-30)% by weight of the soil. The optimal dosages of nano-SiO2 and fly ash were established by employing the outcome of the static test results. The cyclic triaxial (CTX) tests and bender element (BE) tests were carried out to determine the G and D of the composite material and to develop normalized modulus reduction (G/G(max)) and damping ratio curves for the same. The strain-controlled cyclic triaxial tests were conducted for a shear strain range of 0.6-3.0% at a loading frequency of 1 Hz and an adequate confining pressure of 100 kPa. The findings indicated that with the rise in cyclic shear strain (gamma), the G decreases while the damping ratio increases. The hyperbolic models were used to build the curve fitting between the G/G(max) and the damping ratio curve with various gamma. As a result, the correlations between the empirical models fit the database well. The established correlations can be suitable for predicting the seismic behavior of the nano-SiO2 and fly-ash-treated clayey soil under various strain conditions. Furthermore, the carbon footprint and cost analysis of nano-SiO2 and fly ash treated clay soil were compared with the traditional stabilizers. The use of nano-SiO2 and fly ash in stabilizing the clayey soils contributes toward sustainable development and a reduced carbon footprint.
