Effect of fiber on shear strength of municipal solid waste

This study concentrates on effect of tensile strength of fibers on shear strength of municipal solid wastes in Kahrizak landfill. These studies consisted of large scale triaxial tests in consolidated – undrained state on the new and aged (9 years aged) solid wastes in Kahrizak landfill. At first, strength properties of samples in existing condition were determined, then in order to investigate the effect of fibers on shear strength of waste, plastic fibers with 3 different tensile strengths (7, 16 and 21 MPa) with different weight contents (%12) were added. The results showed that waste’s fibers are one of the main providers for waste mass strength and with increase in tensile strength of fibers, the effect of this part in shear strength of landfill will increase, for example, with 200 percent increase of tensile strength in fibers, excessive stress will increase more than 100 percent. Application of plastic fibers in samples will lead to decrease of adhesion and increase of internal friction angle of samples. Also, other than the tensile strength, elasticity and deformations of fibers before the failure have an influence on the behavior of solid waste mass.