| The use of non-woven geotextiles has been increasing exponentially since the 1970s. Due to the lack of understanding in the structural characteristics of non-woven geotextiles, the semi-empirical design of non-woven geotextiles used in different fields of applications are still being used. The engineering parameters used in such design are frequently typical or nominal values determined in standard laboratory conditions. However, satisfactory engineering performance will be compromised when the actual design conditions are different to the laboratory conditions. Therefore, there is an urgent need for research in characterizing the structural properties of non-woven geotextiles.;In this investigation, pioneering research is conducted in the characterization of the fiber orientations of non-woven geotextiles by a three dimensional model of orientation tensor which is based on quantitative stereological measurements determined from three orthogonal sectioning planes. Important engineering properties such as compressibility, tensile strength and modulus, in-plane and cross-plane permeabilities are determined by uniquely designed apparatuses. The measured engineering properties of non-woven geotextiles are compared favorably with the predictions based on models developed by the results of three-dimensional orientation tensor analysis. It is demonstrated in this study that the results of orientation tensor are not only simple and accurate representation of the fiber orientation, but also indicative of their process of manufacturing and engineering performance. |
