Performance of Shred Tire Mixed with Railway Subgrade in Reduction of Train Induced Vibrations

In this study, the performance of shred tire mixed with railway subgrade is evaluated to reduce environmental vibrations caused by trains’ passage. Since incorporating the Shred Tire seeds in soil affects on its shear strength and deformability parameters so, the first stage of the study was allocated to conducting a series of laboratory tests such as the unconfined compression test, and CBR and cyclic plate loading tests on the base material of GW-GC in combination of tire derived aggregates with particle size ranged from 0.475 to aggregation 2.5 cm in four various percentage of 0,5,10 and 15. Moreover, the cyclic plate loading tests were accomplished to determine the mixture elasticity modulus in the second loading cycle as Ev2.By using the obtained values of shear strength as well as deformability parameters obtained in the lab, a 2D numerical model of ballasted track was established under step loads corresponding to a passenger bogie. The numerical results showed that due to increase in shred tire percentage from 5 to 15 percent, the vertical vibration velocity at the ballast shoulder decrease up to 44.56 percent while this value reach to 44 percent for a point with 5 m distance from track shoulder. As a practical result an equation was proposed to show the relation between shred tire percentage and value of environmental vibration.