Utilization of Shredded Waste Tire as a Substitute for Gravel in Stone Column Groups

The present study investigates the load-carrying capacity response of gravel-shredded tire stone column groups as a strategy for strength improvement in loose soils. The experimental study was conducted using large-scale oedometer tests on the stone column groups of gravel and gravel-shredded tire mixtures of different tire content, arrays, and spacings. Also, the efficacy of shredded tire addition on the stone column group bearing behavior was explored using the unit cell concept. To this aim, the entire area of the unit cell was loaded to determine the stiffness of the improved bed soil while applying load directly on single stone columns was done to evaluate the load-carrying capacity of the reinforcing elements. The results demonstrate enhancements in the load-settlement behavior of the stone column groups in mixtures containing 20% of the shredded tire, while further tire addition can adversely affect it. Additionally, adding an optimum shredded tire to the stone column materials leads to an increase in stiffness (Young’s Modulus) of the bed soil. This behavior is directly correlated with the created friction angle and area ratio (A/A S ) of different arrangements of the stone column groups.