Shear strength and deformation characteristics of corn husk fiber-reinforced loess

The use of corn husks to reinforce loess can turn discarded corn husks into a valuable resource and save the cost of loess reinforcement. This study measured and analyzed the shear strength and deformation of corn husk fiber (CHF)-reinforced loesses with five reinforcement ratios, five compaction degrees, and four normal stresses. For the reinforced loess, the shear stress-shear displacement curve changes from strain softening to strain hardening with the increasing normal stress. Compared with the friction angle, the addition of CHFs has a greater effect on increasing the cohesion. The optimal reinforcement ratio is typically 0.3%. However, the optimal reinforcement ratio will increase under high compaction degree and high normal stress. Generally, as the shear displacement increases, the vertical displacement first increases in one direction (positive or negative) and then tends to stabilize. However, for the reinforced loess at 100% compaction degree under the normal stress of 300 kPa, the vertical displacement first increases along the negative direction and then increases along the positive direction to a positive value, indicating that the loess first undergoes shear contraction and then shear expansion. As the compaction degree of reinforced loess increases, the shear expansion phenomenon becomes more significant, or the shear contraction phenomenon becomes less significant. The shear expansion or shear contraction phenomenon becomes less significant as the reinforcement ratio increases, indicating that increasing the reinforcement ratio within the effective range can suppress the deformation of loess. This study provides theoretical support for the use of corn husk to reinforce loess.