Model tests on drainage of pipes wrapped with woven and nonwoven geotextiles

Drainage through pipes plays an important role in tailings pond projects. Reductions in drainage capacity and even clogging of drainage pipes are common issues, especially in tailings projects. To address these clogging issues, a drainage pipe with a replaceable porous-foam filter core (referred to as DPRF) is proposed. This paper studied the drainage characteristics of DPRF wrapped with a woven geotextile and traditional drainage pipes wrapped with a nonwoven geotextile (referred to as DPNG) in fine tailings sands with a reduced scale model test. The results showed that the woven and nonwoven geotextiles could successfully retain fine tailings sand; however, the woven geotextile easily clogged as the experiment progressed. For the DPRF wrapped with a woven geotextile, the larger the aperture of the woven geotextile, the higher the drainage rate of the pipe. The average drainage rate of the DPNG was larger than that of the DPRF wrapped with the woven geotextile. It can thus be inferred that the DPRF wrapped with the woven geotextile is not a good solution to prevent physical clogging. Alternatively, it is suggested that the DPRF wrapped with the nonwoven geotextile can be used to alleviate chemical clogging problems.