H. Ghiassian - Iran University of Science and Technology
R. Jamshidi Chenari - Faculty of Engineering, Guilan University
H. Shahnazari - Iran University of Science and Technology
A. Tabarsa - Civil Engineering Department, Golestan University

A fiber reinforced soil behaves as a composite material in which fibers of relatively high tensile strength are embedded in a matrix of soil. Shear stresses in the soil mobilize tensile resistance in the fibers, which in turn imparts greater strength to the soil. This strength mobilization is highly dependent on the level of confining pressure. In this paper a study on the influence of synthetic fibrous materials in improving the dynamic strength characteristics of a fine sandy soil under low confining pressure is reported. The project is aimed at converting fibrous carpet waste into a value-added product for soil reinforcement. A series of shaking table tests using laminar box were carried out on Toyoura sand specimens reinforced with randomly distributed geotextile strips. The dynamic strength characteristics of the reinforced sand are defined in terms of shear modulus and damping ratio. The effect of fiber content under low confining pressure has been delineated. The results indicate the effectiveness of the reinforcement in improving the dynamic properties of fine sand under low confining pressure.