Evaluation of Woven Geotextile Pore Structure Parameters Using Image Analysis

Filtration performance of woven geotextiles is strongly related to their pore structure parameters, i.e., percent open area (POA) and pore-opening size distribution (PSD). Current methods of determination of pore structure parameters contain inherent disadvantages, whereas image analysis, taking advantage of the two-dimensional structure of woven geotextiles, can be used effectively for this purpose. Two new image-based PSD determination methods and a new image-based POA determination method were developed specifically for woven geotextiles and are presented in this paper. The POAs and two characteristic pore-opening sizes, O95 and O50, of various woven geotextiles were determined using the information provided by the image analysis methods. The image-based POAs and O95 pore-opening size of various geotextiles are comparable to those obtained from the physical measurements and the values reported by the manufacturers. On the other hand, the measured O50 pore-opening size is higher than the one determined using the analytical equations developed by two previous researchers.