The viscoplastic behaviour of a geogrid-reinforced model wall

The paper deals with the time-dependent behaviour of retaining walls reinforced with polypropylene geogrids and subjected to increasing loads applied to the soil surface behind the wall. The experimental programme involved fully automatic small-scale 1g physical models of a geogrid-reinforced wall. Long-term model tests were carried out using different plate loading rates in order to investigate the time-dependent response of the reinforced walls. The paper presents details of the physical model, testing procedure and principal test results. An analytical interpretation of the time-dependent viscoplastic behaviour using a simple three-parameter time-rate equation is shown to fit the experimental data, and is then proposed to predict the long-term displacements of the reinforced walls.