排水钉工作机理的模型试验研究
Model test and study on the working mechanism of drainage nail

目前大多数边坡采用传统PVC排水管，短时间服役后，常发生堵塞和土颗粒流失，导致排水失效。为研究一种长期高效的新型排水系统——排水钉，在室内开展排水钉与传统排水管的长期排水试验，测试排水钉的毛细作用，分析2种排水系统的排水速度、综合渗透系数、砂土颗粒级配的变化规律以及排水钉的毛细作用效果。研究结果表明：经过若干次干湿循环后，排水钉排水性能良好，而传统排水管排水性能却明显降低；排水钉能促使其周边砂土形成5~10 cm的天然反滤层；排水钉-土的耦合作用增强了砂土毛细作用。
At present, most of the traditional PVC drainage pipes don’t work after a short period of use because of clogging and soil-particles lost. To study a long-term and efficient new drainage system, drainage nail, a long-term drainage test of drainage nail and traditional drainage pipe was carried out, and the capillary action of drainage nail was tested. In this paper, the drainage velocity, comprehensive permeability coefficient, the variation rule of sand particle gradation and the capillary effect of drainage nail were analyzed. The results show that the drainage performance of drainage nail is good after several dry-wet cycles, and traditional drainage pipe’s drainage capacity decreases significantly. The drainage nail can make the surrounding sand form 5~10 cm natural anti-filtration layer. The capillary effect of sand is strengthened by the coupling of the drainage nail and soil