Laboratory evaluation of water absorption and drainage performance of a new wicking geotextile in loess-sand mixtures

Climatic warming and humidification in Northwest China have led to frequent extreme rainfall events, triggering numerous geohazards along linear infrastructure such as highways in the Loess Plateau region. A self-developed wicking geotextile with fibers featuring an irregular cross-section (14 μm in major axis, 7 μm in minor axis) was first introduced to facilitate drainage in loess-sand mixtures, thereby enhancing the strength and stability of foundations. Capillary effect and drainage tests were conducted to evaluate its water absorption and drainage performance of loess-sand mixtures with various ratios of poorly graded sand with silt. Additionally, evaporation tests were performed to assess the evaporation rate of the wicking geotextiles under different environmental conditions, including variations in temperature and humidity. The results showed that: 1) the maximum liquid vertical wicking heights of the wicking geotextiles in loess-sand mixtures increased with both sand contents and initial water contents; 2) the evaporation rate decreased with increasing humidity, but increased with increasing temperature; 3) Under simulated extreme rainfall, the drainage efficiency of the wicking geotextile improved with greater sand content. The drainage mechanisms of the wicking geotextiles in loess-sand mixtures were analyzed based on fibers’ microstructure. This study contributes to geohazard mitigation in the Loess Plateau.