Assessment of Wicking Geotextiles for Enhanced Drainage and Reinforcement in Flood-Prone Coastal Highway Slopes

Flooding significantly compromises coastal transportation infrastructure by increasing the risk of slope failures and causing substantial damage. Rapid escalation in the severity and occurrence of flooding highlights the need to develop techniques for effective water drainage within slopes to ensure their safety and durability. Over the past decade, the multifunctional wicking geotextile has gained popularity in geotechnical infrastructure design. Its enhanced moisture redistribution capabilities, facilitated by wicking action, enable it to effectively drain accumulated water within geomaterials. Although wicking geotextiles have demonstrated promising results in pavement applications, their performance in highway embankment slopes remains largely unexplored. This project aims to evaluate the effectiveness of wicking geotextiles as a solution for coastal infrastructure susceptible to flooding. The research focuses on understanding the effect of flooding and drainage on the interface strength of wicking geotextile, a crucial parameter in the design of reinforced slopes. A large-scale direct shear box was used to conduct interface tests with wicking geotextile. Tests were performed immediately after flooding and after 7 days to capture the effects of wicking-induced drainage on interface strength properties. The drainage capability of wicking geotextile was also evaluated at different normal stress levels. Additionally, a finite element model was developed, and numerical analyses were conducted to examine effect of interface strength properties of wicking geotextile on safety factors of the slope subjected to flooding. Results from experimental and numerical studies indicate that wicking geotextile has potential to improve the stability of slopes vulnerable to flooding.