Shear strength characteristics of basalt fiber-reinforced loess

Loess owns the characteristics of collapsibility, disintegration and solubility, which pose a challenge to engineering construction. To examine the shear strength of basalt fiber-reinforced (BFR) loess, consolidated undrained (CU) triaxial tests were conducted to explore the impacts of water content (w), fiber length (FL), fiber content (FC) and cell pressure (σ(3)) on the shear strength. According to the results, the shear strength model was established taken into account the impacts of FL, FC, and fiber diameter (d). The results showed that the peak strength of BFR soils enhanced as FL, FC, and σ(3) increasing, whereas it decreased with increasing of w. Compared to unreinforced soil, the peak strength of BFR loess improved 64.60% when FC was 0.2% and FL was 16 mm. The optimum reinforcement condition for experimental loess was that of FL was 16 mm and FC was 0.8%. The reinforcing mechanism of fibers was divided into a single tensile effect and spatial mesh effect. The experimental and calculated results agreed well, which suggested the model is suitable for predicting the shear strength of BFR loess. The research results can offer a guideline for the application of BFR loess in the subgrade and slope engineering.