A simple method for estimating Poisson's ratio of geosynthetics at zero strain

Abstract

A theoretical expression for the Poisson’s ratio of geosynthetics as a function of axial normal strain may be very useful, particularly during the initial design stage of some geosynthetic-related projects. This technical note examines the suitability of such an expression suggested by Giroud 2004 (Geotext. Geomembr., Vol. 22, No. 4, pp. 297–305) in detail, and suggests a simple approach to estimate the appropriate values of the Poisson’s ratio of the geosynthetics at zero strain (ν0), which are required for use of this expression. A chart is presented for this purpose, which can be used by knowing the experimental value of the Poisson’s ratio of a geosynthetic at any one nonzero strain. The suggested procedure and proposed chart can equally be applied for estimating ν0 of other similar materials. Based on the limited experimental results presented in this note, the Giroud’s expression is recommended for use with ν0=0.57 for the high density polyethylene (HDPE) geomembranes and ν0=1.75 for the nonwoven geotextiles, assuming that these values will not differ significantly for other similar geosynthetics, because ν0 is dependent only on the nature of material.