Relevant properties of geosynthetic reinforcements on the interaction behavior under static and cyclic load conditions
The application of geotextiles as soil reinforcement in roads, embankments and inclined to vertical earthen wall constructions has proven a valid and very beneficial technique in the last decades. Many different products are available on the market, such as geogrids or wovens, made from different raw materials and/or using different production technologies. This paper focuses on the relevant proper-ties of geosynthetic reinforcements on the interaction behavior under static and cyclic load conditions. In different researches and publications it has been concluded, that the ability of a reinforcement product to align itself to the soil particles or soil surface, respectively, has a beneficial effect on the interaction be-havior. Especially under cyclic loads, such as in road or railway applications, the capability to align has been shown beneficial. The paper gives an overview on related literature and explains the beneficial ef-fect of a high alignment capacity of reinforcement products on the performance of the composite material “reinforced soil”.
The adaptability of geogrids to the particles or ground surface is beneficial for the load transfer between soil and reinforcement. The effect can be especially observed under cyclic loading, where the flexibility of the geogrid allows the material to reach a high density and little or none cavities remain. At the same time the particles are confined due to the alignment of the geogrid and the resulting deviation of the ten-sile forces, which leads to horizontal and vertical components. Rigid geogrids in contrast, are capable to bridge small distances between particles. Those small bridges and the remaining cavities result in partially elastic response to actions, since those bridges are acting like springs. The main properties and characteristics of a geogrid as reinforcement are tensile modulus, tensile strength and the interaction behavior with the soil. As reported above, the interaction behavior is domi-nated by the frictional interaction, interlocking and also the adaptability of the geogrid to the unevenness of the soil surface or particles. The capability of a geogrid to have frictional interaction and interlocking with soil in combination with the adaptability to unevenness can be named “interaction flexibility”.