Geotextile friction mobilization during field pullout test

Abstract

Small-scale laboratory tests may not yield reliable values for soil–geotextile interface properties due to the effect of scaling. Field tests offer a better alternative to overcome this problem. In situ pullout tests were performed on a full-scale embankment built over a woven polyester geotextile sheet. The field tests were conducted using different fill heights of compacted clayey soil. The performance of the geotextile was examined when the base soil underneath the geotextile was stiff clay of high plasticity or compacted clean river sand. The test section was instrumented to monitor the geotextile movement and the applied pullout force. Results of the tests showed a linear increase in the geotextile frictional resistance with the increase in the fill height. Also, a successive movement response at different locations on the geotextile away from the loaded edge was detected during the early stages of loading. At the slippage load, a continuous rigid body translation occurred in the geotextile sheet without any further increase in the applied pullout force. The suitability of a widely used interface numerical model that consists of a zero-thickness joint element and a nonlinear elastic hyperbolic stress-deformation material model was examined using the finite element technique. The results showed the inadequacy of this model to deal with large deformation problems typically experienced in geosynthetic reinforced soils.