A series of triaxial compression tests were performed in an attempt to evaluate the bene ts of plastic wastes and investigate the engineering properties of sand reinforced with such materials. In this research, the e ects of the contents (0, 0. 25, 0. 5, 0. 75, and 1% of the dry weight of sand) and types of plastic wastes (Poly-Ethylene Terephthalate (PET) and Poly-Propylene (PP) bers) as well as the con ning pressures (50, 100, and 200 kPa) on the sand behavior in Babolsar, Iran were investigated. The values for deformation modulus (up to 84%), peak (up to 7 times of the unreinforced sand), and steady state shear strength increased upon reinforcement. Moreover, axial strain at failure for ber-reinforced sand increased up to 1. 5 times its unreinforced counterpart (from 3. 36% to 8. 53% for 1% PP usage at con ning pressure of 50 kPa). Generally, it can be concluded that using plastic wastes in the sand would result in low-cost soil reinforcement and a reduction in the disposal problem of these kinds of wastes.