Drainage performance and capillary rise restraint effect of wicking geotextile

Wicking geotextile (WG) is considered as a possible countermeasure to reduce water content in unsaturated soil. In this research, rainfall tests were carried out to verify the drainage performance of WG. And capillary rise tests were conducted to study the effect of WG on the prevention of capillary rise. Test results indicated that WG with good drainage performance could drain gravitational and capillary water out of kaolinite soil. For kaolinite soil column with water content of 12% and compaction degree of 90%, the whole process of capillary rise in soil column with a layer of WG was a typical two-stage mode, and the maximum capillary height was about 380 mm, which provided that the WG could work as a barrier to prevent capillary rise effectively. In addition, the total vertical influential regions of WG in kaolinite soil above and below the WG layer were 400 and 100 mm, respectively.