Theoretical and Experimental Opening Sizes of Heat-Bonded Geotextiles

The structure of nonwoven heat-bonded geotextiles is analyzed using a geometrical probability approach. An expression of the pore size distribution of these filters is derived from basic manufacturing parameters. Two experimental techniques used to evaluate fabric opening size—dry sieving of glass beads and hydrodynamic sieving of soils—are investigated and the results compared to the calculated opening size obtained using the pore size distribution equation. Excellent agreement has been found between the calculated opening size and the filtration opening size measured with the hydro dynamic sieving technique.