Comparative Study of Wicking and Conventional Geotextiles: Interface Properties and Drainage Performance for Slope Reinforcement

Coastal infrastructure is becoming susceptible to failures due to rise in the frequency of flooding events caused by adverse weather phenomena. Water infiltration into the soil during an extreme rainfall event greatly decreases its suction, causing instability and probable collapse of geotechnical structures. The risk of potential damage to coastal highway infrastructure caused by flooding emphasizes a need for the implementation of innovative materials or methods which can rapidly and effectively drain geomaterials during and after flooding events. Wicking geotextile, made up of hydrophilic and hygroscopic fibers, is a novel geosynthetic which has been proven effective in removing moisture from pavement subgrades. While non-woven geotextiles are commonly used for drainage applications in slopes, this study evaluates and compares the performance of wicking geotextiles as reinforcement and drainage element against traditional non-woven geotextiles. Both drainage and interface properties of a wicking and non-wicking geotextile were determined using a large-scale direct shear apparatus. Tests were conducted at varying stress levels, and drainage capabilities of both geotextiles were examined using moisture sensors embedded in soil samples. The results from the tests indicate that wicking geotextile provides superior drainage and reinforcement capabilities compared to conventional non-woven geotextile.