| Nonwoven geotextiles are widely used in water conservancy projects such as reservoir cofferdams,earth-rock dams,embankment slopes,and relief wells because of their good functional characteristics such as filtration,drainage,isolation,seepage,protection and reinforcement.However,in engineering practice,due to the clogging of geotextiles,the problems of filtration and drainage failure,and the destruction of engineering safety and stability have occurred frequently.Therefore,in view of the clogging problem of nonwoven geotextiles,this paper uses several clogging test devices to carry out the experimental study on the infiltration and clogging of multiple sets of geotextiles.In addition,this paper further studies the clogging mechanism of geotextiles and the evaluation index of clogging,which hopes to provide a reference for the study of geotextile clogging and the selection of geotextiles in engineering.The main research contents and conclusions of this paper are as follows:(1)A series of conventional infiltration and clogging tests of geotextiles were carried out.Through the test parameters such as the gradient ratio GR,the permeability coefficient k_G~S and unit volume containing soil amount of fabricμ,the influence of different factors such as soil clay content,fabric equivalent pore size,soil sample density and hydraulic conditions on the infiltration and clogging characteristics of geotextile are analyzed.(2)A long-term infiltration and clogging test of several sets of geotextiles was carried out.Through the comparative analysis with the results of conventional clogging tests,it is considered that there is a limitation in determining whether the pressure head and the seepage flow are stable in the conventional infiltration and clogging test as the basis for judging the end of the infiltration and clogging test.(3)Through the particle flow comparison analysis method,the causes and mechanism of different geotextile clogging types were discussed.Combined with the analysis of the results of the clogging test,the rationality of the method is further verified,which provides a reference for the subsequent research on the mechanism of geotextile clogging.(4)Combined with the analysis of the mechanism of geotextile clogging,the relationship between the different clogging conditions of geotextiles and the test parameters such as gradient ratio GR and unit volume containing soil amount of fabricμis discussed.It is also suggested that the gradient ratio GR and the unit volume containing soil amount of fabricμin the long-term infiltration clogging test are used as the evaluation index of geotextile clogging. |
