Abstract: The phenomenon of geotextile clogging often occurs in the waterproof and drainage system during the waterrich tunnel operation. To solve the problem of drainage performance failure caused by geotextile clogging during the tunnel drainage system operation, the shortcomings of existing geotextile clogging tests are analyzed. Therefore, an indoor scale model test device for tunnel geotextile clogging is designed and developed based on the characteristics of tunnel arch section type and indirect arrangement of circular drainage pipe. Then, the seepage and clogging tests are conducted on the types and layers of geotextiles and clogging types. The test results show the following. First, the unit time flow at the arch waist is greater than that at the arch shoulder and the arch crown for the geotextile at the same crosssection of the tunnel; moreover, the clogging at the arch waist is the most severe. Second, the chemical and physical resistances of polyester filament and staple geotextiles are the same. However, the water permeability and soil retention of polyester filament are better than that of polyester staple geotextile. Third, with the increasing geotextile layers, the overall drainage performance and anticlogging ability of geotextile increase, and the increasing range gradually reduces.  Furthermore, clogging of the geotextile above the circular drainage pipe is more severe. Finally, the influence of chemical clogging on geotextiles is larger than that of physical clogging.

Key words: water-rich tunnel, geotextile, seepage clogging, test device