Unconfined compression strength and mesostructure of reinforced soil with wheat straw

摘要

For investigating the compression strength characteristics of the soil reinforced with wheat straws and its deformation and failure mode, unconfined compression strength (UCS) tests were carried out by changing the content and length of wheat straws. The mesostructure changes in the reinforced and unreinforced soil specimens during loading were compared and analyzed by using the computed tomography (CT) scanning. The results showed that the relationship curves between the axial stress and the strain of both soil specimens were the stress-softening type. The addition of wheat straws could effectively control the radial deformation of the soil specimens and improve their UCS. With an increase in the axial strain, the ability of the reinforcement to resist deformation was gradually increased to weaken the tendency of forming cracks through a plane. With the optimum content and length of wheat straws, UCS of the soil specimens reached the maximum value which was about 2.1 times that of the unreinforced soil samples. The CT scanning results also showed that the reinforcement with wheat straws could restrict soil deformation and crack growth. These results can provide references for the application of soil reinforcement with wheat straws in the geotechnical engineering field such as slope protection and ecological slope protection.