Abstract: To improve the strength and resistance to desiccation cracking of clayey soils in engineering practice, fiber-reinforced soils are made by mixing polypropylene fibers together with soils. The polypropylene fibers and kaolin are mixed together and statically compacted into fiber-reinforced kaolin in the laboratory. Then the influences of fiber incorporation on the consolidation and compression characteristics of the fiber-reinforced soil are studied by one-dimensional compression experiments. Test results indicate that both the coefficient of consolidation and compression modulus first increases and then decreases with the increase of the fiber content, under constant dry density and fiber length. When the fiber content is 0.2%, the coefficient of consolidation will reach a peak value. When the fiber content is 0.1%-0.15%, the compression modulus will arrive at a peak value. The coefficient of consolidation first decreases and then increases with the increase of the fiber length under constant dry density and fiber content. When the fiber length is 10 mm, a minimum value of coefficient of consolidation will be achieved. When the vertical pressure is relatively high (≥400 kPa), the compression modulus of the fiber-reinforced kaolin will decrease with the increase of the fiber length. Furthermore, generally the compression index of the fiber-reinforced kaolin increases with the increase of the fiber content. However, a minimum value of the compression index is found when the fiber content is 0.15%-0.2%, or the fiber length is 10 mm.

Key words: fiber-reinforced soil, polypropylene fiber, kaolin, consolidation test, compressibility