Geotextiles have been used successfully as filters [for cross plane flow], drains [for plane flow], or both. Geotextile drainage occurs either cross plane or in-plane. In regard to drainage, the cross-plane permeabilities of all the geotextiles currently in use are sufficient for most situations. But it is not meaningful if geotextiles are subjected to dynamic load. The selection of geotextile criteria give empirical limiting values to the ratios of geotextile pore size to the soil particle size. Under dynamic loading condition, they do not give a quantitative measure of the amount of contamination likely to occur in railway ballast materials due to mud pumping. In this investigation in-plane permeability at various stress levels and cross plane permeability tests on geotextiles were conducted. In addition a series of simulated mudpumping tests in soil dynamic tester were conducted using various combination of soil and geotextiles. The effect of stress level on in-plane permeability and the effect of type of soil and geotextile and frequency of load application on SCV and deformation was studied. Various criteria used for geotextiles for reversible flow conditions were used to check whether the geotextiles satisfy the criteria. The SCV were considered in each case. An attempt is made to correlate SCV to the criteria based on the pore size of the geotextile and particle size of the soil.
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