COMPARATIVE EVALUATION OF NATURAL AND SYNTHETIC GEOTEXTILE REINFORCEMENT IN SAND USING SCPT AND DCPT

Abstract

The use of geotextile reinforcement has been increasingly adopted as a practical and economic approach for improving the mechanical response of non-cohesive (granular) soils in unpaved and lightly trafficked pavement systems. The synthetic geotextiles have been extensively studied and widely implemented owing to the high tensile strength and durability. The natural geotextiles namely, jute and coir offer sustainable and environmentally favourable alternatives. In the present study, a laboratory based experimental work was undertaken to examine the reinforcing behaviour of natural geotextiles (jute and coir) in compared to a synthetic geotextile placed over a sandy subgrade. Static Cone Penetration Tests (SCPT) and Dynamic Cone Penetration Tests (DCPT) were employed to evaluate the influence of reinforcement type, tensile stiffness, placement depth, and layering configuration on penetration resistance, stiffness mobilisation, and confinement behaviour. A digital SCPT device was used to obtain detailed penetration resistance profiles under controlled conditions, while DCPT provided complementary insights into the response of the reinforced system under dynamic loading. The comparative charts prepared using experimental results show that the inclusion of geotextile reinforcement leads to a significant improvement in cone resistance and penetration characteristics of the sand. Synthetic geotextiles exhibit higher peak resistance, primarily due to their greater tensile modulus, whereas natural geotextiles demonstrate significant improvement in near-surface stiffness through enhanced frictional interlock and confinement effects. The observed experimental response indicates that, under appropriate placement conditions, natural geotextiles are capable of delivering meaningful reinforcement benefits in unpaved pavement systems.