Effect of Specimen Size on the Dynamic Properties of River Sand and Rubber Tire Shreds from Cyclic Triaxial and Cyclic Simple Shear Tests

The recent studies focus on the sand and rubber tire shred mixtures for their application as seismic base isolation of buildings. The dynamic properties such as shear modulus and damping ratio of these materials are very important for the seismic soil-structure analysis. Cyclic triaxial testing is widely used to determine the large-strain dynamic properties of soils. However, the cyclic triaxial tests do not represent realistic stress conditions during the ground motion. The cyclic simple shear tests which best represent in situ seismic stress conditions are mostly used for liquefaction assessment and seldom used for finding the dynamic soil properties. The size of the specimens used for both types of tests is dissimilar and hence is presumed to have an effect on the shear modulus and the damping ratio. This study highlights the possible effect of specimen size on the dynamic properties of the river sand and rubber tire shreds and an optimum sand–rubber tire shred mixture obtained from the cyclic simple shear tests and cyclic triaxial tests.