Abstract: Sand soil mixed with waste tire shreds can be used as filling of subgrade, retaining wall or shock isolation system of base etc., which has many advantages, such as small earth pressure, good absorption of vibration, excellent durability and low cost. There are comparison between the mixture and the sand soil through digital dynamic triaxial tests, which mainly include the influence of the tire shred content and the confining pressure on the dynamic strength, dynamic elastic modulus and equivalent damping ratio. The results show that when the confining pressure and the dynamic shear stress ratio are equal, the dynamic strength of the mixture is slightly lower than that of the sand soil which is reduced by 20 kPa, 8%. The dynamic elastic modulus of the mixture obviously decreases with 22 MPa, 60% of the maximum reduction. The equivalent damping ratio of the mixture firstly increases, then decreases with the increasing of the tire shred content; the critical tire shred content is about 30%-40%. The mixture’s maximum increment of equivalent damping ratio is about 91%. Test results confirm that the shearing rigidity of the mixture can effectively reduce, which can exploit the advantage of the absorption of vibration to the full.

Key words: mixture soil, tire shreds, dynamic strength, dynamic elastic modulus, equivalent damping ratio