Liquefaction Potential and Dynamic Properties of Sand-Tyre Chip (STCh) Mixtures

This paper presented the results of the investigations on the liquefaction potential and the dynamic properties of sand-tyre chip (STCh) mixtures. A series of strain controlled consolidated undrained cyclic triaxial tests were carried out on specimens of sand mixed with varying proportions of tyre chips (TCh). The specimens of STCh mixture were prepared at a constant initial relative density and tested at an effective confining pressure of 69 kPa. The results show that TCh significantly reduces the liquefaction potential of sand with the addition of gravimetric proportion of TCh between 20 and 40 % to sand. The maximum shear modulus (Gmax) of the STCh mixture was determined by bender element tests for different gravimetric proportions of TCh and effective confining pressures. The initial shear modulus has been found to be influenced by the proportion of TCh and confining pressure. The shear modulus degradation and damping ratio curves were developed for dynamic analysis of sand-scrap tyre mixtures. The increase of scrap tyre in sand-scrap tyre mixtures reduced the shear modulus degradation and increased the damping ratio.