Reinforcement with geosynthetics – how they work in soil

Geosynthetics in the form of fabrics and nonwovens and have been used successfully for around 50 years for the reinforcement of base layers in traffic route construction and the construction of smaller but steep wrap around walls. Due to the development of high-strength geogrids, the field of appli-cation has expanded enormously today. In addition to classic applications with now impressive dimen-sions, geosynthetic reinforcements are mainly used for bridging areas at risk of sinkholes and for the foundation of embankments on soft ground in various designs. Compared to conventional concrete con-structions, this is usually done with considerably less effort and also with less use of resources and energy. Geosynthetic reinforced constructions show an extremely ductile behaviour, which makes them very ro-bust against settlements and settlement differences. It is also known from many measurements and obser-vations that geosynthetic reinforced constructions usually have a higher load-bearing capacity and exhibit lower deformations than are calculated during design. This indicates that the interaction mechanisms be-tween soil and geosynthetics are not yet sufficiently understood. In this paper the different interactions be-tween soil and geogrids are shown on the micro- and macroscale. The relative movement between geogrid and soil is of enormous importance. As far as possible, mechanical models for the interaction mechanisms on these two scale levels are presented. Subsequently, for the main application of geosynthetic reinforced constructions, the practical effects of these models will be shown. Finally, the existing research needs are identified. There is great hope here in the use of transparent soil, with which it is possible to make the rel-ative movements between geogrid and soil inside a test box visible without distortion of the result by measuring equipment.