Investigating the Effect of Loading Frequency on the Dynamic Properties of Sand-Tire Powder Mixture Using Shaking Table Tests

Today, the use of waste tires has been expanded in various geotechnical projects to absorb and reduce the vibration caused by seismic and dynamic loads, and therefore it is important to study the effect of different parameters on their behavior and dynamic characteristics in combination with soil. So this study examined the effects of loading frequency on dynamic properties of sand-‌tire powder mixtures such as shear modulus (G) and damping ratio (D). A series of 1-g shaking table tests were performed on sand-‌tire powder mixture. Tire powders were added to the sand with 5%, 10%, 15% and 20% in gravimetric basis and with a relative density of zero were subjected to sinusoidal loading at frequencies of 0.5, 1, 2, 3, 5, 7 and 9 Hz and at input acceleration of 0.1g and 0.3g. The results showed that in all cases, the increase in frequency in the same cycles increased the shear modulus and the damping ratio. Also, with increasing shear strain, the shear modulus of the mixture decreased, but the damping ratio increased. On the other hand, by increasing the tire powder, the value of the shear modulus is reduced, but the amount of damping ratio is increased.