Mechanical properties of soil reinforced with both lime and four kinds of fiber

Soil was solidified with both lime and fibers to investigate the mechanical properties of the soil. Wheat straw, rice straw, jute and polypropylene fiber was added to the soil and lime-soil respectively. Unconfined compressive test of the fiber-soil was conducted to confirm the optimal fiber content and optimal fiber length. Triaxial compressive test of fiber-lime-soil was carried out to study the shear strength, deviatoric stress-strain properties and sample failure pattern. The results are as follows: Optimal fiber content was 0.2% or 0.25%, and the optimal fiber length was 30% or 40% of the sample diameter. Reinforcement significantly increased the cohesion and lightly improved the internal friction angle. The cohesion increments of polypropylene fiber-lime-soil, jute-lime-soil, rice straw-lime-soil and wheat straw-lime-soil were decreased in turn. The four kinds of fiber may all improve the strength and deviatoric stress-strain properties of soil and lime-soil, in which polypropylene fiber for reinforcement is the best.