Shear strength characteristics of basalt fiber-reinforced loess: experimental investigation and model prediction

Abstract

Abstract 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 (σ3) on the shear strength. The microstructure of reinforced loess was constructed using SEM measurements to reveal the reinforcing mechanism of basalt fibers. According to the results, the shear strength model was established taken into account the impacts of FL, FC, and fiber diameter (d) using the regression analysis method. The results showed that the peak strength of BFR soils enhanced as FL, FC, and σ3 increasing, whereas it decreased with increasing of w. The reinforcing mechanism of fibers was divided into a single tensile effect and spatial mesh effect, and the bridging effect transformed the force, which improved the overall ability of composites to resist deformation and damage. 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.