The use of geosynthetics in embankments and its influence in pavement design of road infrastructures

The main purpose of this article is to analyse how the use of geosynthetics in the subgrade of road pavements, either in embankment or in excavation, can influence the pavement design. The article begins with a brief description of the Portuguese experience related to the use of geosynthetics in the construction and rehabilitation of the main road network. To demonstrate the benefit of the use of geosynthetics in the subgrade, a parametric study was performed by means of the finite element modelling of flexible pavement structures using ADINA software, considering different heavy traffic, weather and subgrade conditions. The reinforcement effect was analysed in terms of the admissible traffic increase and of the thickness reduction of bituminous layers. The study has confirmed that it is possible to obtain a benefit in pavement design when a geogrid is used, mainly when the subgrade quality is low