Mechanical Behaviors of Natural Sand Soils and Modified Soils in Heavy-Haul Railway Embankment

The addition of chemical or mechanical materials, such as fibers or stabilizers, is frequently utilized in geotechnical engineering to improve the mechanical properties of problematic soils. In this study, great efforts have been made to obtain insight into the mechanical properties of the natural, fiber, and chemical additive-stabilized soil in heavy-haul railway embankment. A series of triaxial compression tests are conducted on the stabilized samples of different preparation conditions, including water content, compaction degree, confining pressure, fiber content, fiber length, stabilizer content, and curing time. Results show that the shear strength of natural soils shows a distinct increase after adding fiber and chemical additive stabilization. The optimum fiber content and length for fiber stabilization are 0.2% and 12 mm, respectively. The initial tangential modulus and failure stress of chemical stabilized samples increase with the increase of additive dosage or curing time. Meanwhile, a brittle characteristic is observed. In the process of determining the reinforcement methods in practical projects, several other considerations are included, such as equipment and time available, especially for stabilized soils. The fiber-reinforced soils and stabilized soils are efficient for increasing the shear strength and changing of the brittleness character of the heavy-haul railway embankment. The results of this study could provide a valuable reference for geotechnical engineers dealing with soil problems, especially for the heavy-haul railway embankment