Mechanical, Degradation, and Impact Resistance of a Sustainable Coir Geotextile Composite Barrier for Landslide Mitigation

Flexible barrier systems are widely used for landslide and debris flow mitigation due to their ability to dissipate impact energy through large deformations. Conventional systems, however, rely on steel mesh components, which are associated with high environmental impact and durability concerns. This study examines the feasibility of a sustainable coir geotextile composite barrier as an alternative flexible barrier for mitigating small-to-moderate landslides. A woven geotextile barrier was developed using multi-strand coir ropes and evaluated through a comprehensive experimental program involving physical and mechanical characterization, accelerated degradation testing, incremental static loading, vertical drop impact tests, and sustained load retention tests. The developed barrier exhibited a high mass per unit area of approximately 3750 g/m2 and tensile capacities exceeding 2 kN at the rope level. Accelerated weathering tests revealed a limited reduction in tensile strength of approximately 5% after three years of exposure, whereas prolonged exposure of five years led to strength losses exceeding 70%, underscoring durability as a key design consideration. Static loading tests confirmed stable behavior up to 550 kg, and sustained loading of approximately 1700 kg was maintained over 48 h without loss of structural integrity. Vertical drop tests demonstrated impact resistance in the range of 6–51 kN, depending on the drop height, mass, and connection density. The results demonstrate that coir geotextile barriers can function as flexible, energy-dissipating composite systems suitable for sustainable landslide mitigation in moderate hazard scenarios.