Shear behaviour of soil reinforced with randomly distributed jute and coir fibres

The incorporation of randomly distributed natural fibres into soil matrices offers a sustainable and cost-effective approach for enhancing the mechanical performance of geomaterials. This study presents a systematic experimental investigation of natural fibre–reinforced soil (RDFS), focusing on the use of jute and coir fibres as discrete reinforcements. The shear behaviour of unreinforced soil was directly compared with that of jute- and coir-reinforced specimens to quantify changes in cohesion and angle of internal friction. The results demonstrate that fibre inclusion significantly alters shear strength characteristics, with jute fibres predominantly enhancing frictional resistance, while coir fibres contribute to improvements in both cohesion and ductility. Consistent with existing literature and historical practices, the findings confirm that the addition of a small proportion of natural fibres leads to a substantial improvement in ductile behaviour, unconfined compressive strength, and resistance to cracking. Overall, the study highlights the considerable potential of RDFS as an effective and sustainable ground improvement technique for geotechnical applications.