Application of geosynthetics in the construction of roads and railways: yesterday - today - tomorrow

摘要

Geosynthetics have been successfully used for decades in the construction of roads and railways. They fulfil almost all classical functions like separation, protection, filtration, drainage, sealing and reinforcement. In recent time the scope of application has been extended significantly by the construction of steep slopes and geogrid reinforced bridge abutments, the crossing of areas with soft soil by using geosynthetic encased sand columns and the bridging of areas susceptible to sinkholes. Particularly for the last case geosynthetics with additional features have been developed allowing a permanent monitoring of the deformations. The development of such intelligent geosynthetics with integrated sensors is by no means not at its end. Geosynthetics of the future will be equipped with such additional functions enabling a permanent and non-destructive monitoring of structures built with geosynthetics. In the field of reinforcement applications structures with geosynthetics show significant advantages in terms of economic and ecological aspects against classical concrete structures. It is also well known from large scale experiments and field tests that geosynthetic reinforced constructions have a much higher bearing capacity than calculated and that the deformations are much lower than expected. Therefore, it is quite evident that the compound behavior of geosynthetic and soil is not yet completely understood. Recent research on this topic using large scale triaxial- and biaxial- tests combined with a modern method of visualization of the movement of the soil particles tries to fill this gap.