Long Term Behaviour of An Asphalt Pavement Structure Constructed on a Geogrid-Reinforced Subgrade Over Soft Soils

Abstract

Many roads with asphalt pavement are being reconstructed every year, as their quality becomes insufficient by the requirements. As it is well- known, old roads were built not in the very best quality, so doing reconstruction projects in the most cases there were required to deal with soft soils that are under the existing road structure. Geogrid reinforcement was widely used to solve issues of soft soil in Lithuania. There are projects where geogrid reinforcement is used to control road pavement roughness when there are layers of peat or silt under road structure instead of using concrete piles or geosynthetic-encased soil columns. This type of geogrid reinforcement application is unexplained in any normative-technical document but widely used in Lithuania. This application was usually made constructively without any calculations, choosing the reinforced solution by reducing the geogrid tensile strength or layer quantity compared to reinforced load transfer platform over piles. This paper evaluates the long-term influence of geogrid- reinforced subgrade on the roughness of asphalt surfacing and bearing capacity of the road structure when the soft peaty soils stratify in the deeper layers of the subgrade. There were compared the reinforced sections to adjacent sections to see the effect and fortunately a large number of adjacent sections were also strengthened, mostly by lime stabilisation. Therefore, this comparison allows making more insights on the long-term performance of the strengthened subgrade and influence on the road quality. This research gives recommendations on how the geogrids has to be selected to be used in this kind of application.

Finite-Element Analysis of Strengthening the Subgrade on the Basis of Boring and Mixing Technology

“…Physical modeling is an important part of the research that provides possibilities to correct theoretical foundations. A number of methods exist for solving the problem of strengthening of the subgrade in transport [17][18][19][20][21], one of which is strengthening the subgrade by various methods, which significantly affects the stress state of the track superstructure.…”

Triaxial Test of Coarse-Grained Soils Reinforced with One Layer of Geogrid

“…Geosynthetics are widely employed in diverse infrastructure projects. While their initial applications were focused on soil reinforcement, separation, filtration, and drainage [1,2], geosynthetics have since found expanded utility. They are now employed in preventing asphalt cracks [3,4], addressing significant settlement concerns beneath pile-supported embankments [5], fabricating stone columns [6], constructing shallow strip foundations [7,8], protecting pipelines [9], and reducing CO 2 [10], among other uses.…”