Investigation of the Water-Retention Characteristics and Mechanical Behavior of Fibre-Reinforced Unsaturated Sand

Abstract

The introduction of fibres into soil can effectively improve its engineering properties. Systematically understanding the unsaturated mechanical properties of fibre-reinforced soil is highly significant. Moreover, there is currently no suitable model for describing the water-retention characteristics of unsaturated fibre-reinforced soil. The purpose of this study is to propose a model for the soil–water characteristic curve (SWCC) that can accurately describe unsaturated fibre-reinforced soil. The research focuses on unsaturated sand reinforced with PP fibres. A series of compression and direct shear tests were performed to investigate the mechanical behaviour. In addition, the SWCC was measured using the axis-translation technique. Based on the van Genuchten (VG) model, a modified model considering fibre reinforcement (VG-CFR) is developed for quantitatively analysing the influence of fibre content on the SWCC. The results showed that the established VG-CFR model can reflect the water-retention characteristics of fibre-reinforced sand.