Experimental study of the influence of laying method on the drainage performance of a new geotextile

The new geotextile is a type of geomaterial with high drainage performance, which can drain water from the subgrade more efficiently and completely than traditional geotextiles. At present, although the drainage mechanism of this new geotextile has been studied, the influence of the laying method on the drainage performance of the geotextile has not been systematically studied. In view of this, based on the weave structure of the new geotextile, the drainage mode and the ink dissipation tests, and by laying a layer of geotextile in sand, the comparative drainage tests were carried out under different laying methods. Then the influence of different laying methods of the geotextile on the cumulative amount of water, the wetting front and the moisture content (both volumetric and gravimetric) were evaluated. The results show that the cumulative amount of water for the new geotextile, when laid horizontally and vertically upwards, the new geotextile laid horizontally and vertically downwards, and the traditional geotextile laid horizontally and vertically downwards is 12.23%, 10.41% and 5.97% higher than that of sand-free drainage, respectively. The drainage performance of the new geotextile is influenced by its laying method, the best drainage performance is achieved when the new geotextile is laid in a horizontal and vertical upward direction. When the new geotextile is laid horizontally and vertically upwards, it not only increases the drainage path, but also expands the drainage influence area, so that a certain moisture difference of sand is formed, and then the resulting suction difference could drive the water migration, coupled with the capillary action of the new geotextile, more water would be exported. When the sand drains freely, the water would be discharged along the pore. When the traditional geotextile is embedded in sand, although it increases the drainage path and accelerates the drainage efficiency, it is a water-repellent material and has low drainage performance in an unsaturated environment. The research results could provide a reference for the design and construction for this geotextile to deal with subgrade problems.