Triaxial Polypropylene Gravel Driveway Geogrid

Application and Associated Functions of Geosynthetics in Roadway Systems

ROADWAY DESIGN USING GEOGRIDS

Certain design principles are common to all types of roadways, regardless of the design

method or the type of geosynthetic (i.e., geotextile or geogrid). Basically, the design of any

roadway involves a study of each of the components of the system, (surface, aggregate base

courses and subgrade) detailing their behavior under traffic load and their ability to carry that

load under various climatic and environmental conditions. All roadway systems, whether

permanent or temporary, derive their support from the underlying subgrade soils. Thus,

when placed at the subgrade interface, the geosynthetic functions are similar for either

temporary or permanent roadway applications. However, due to different performance

requirements, design methodologies for temporary roads should not be used to design

permanent roads. Temporary roadway design usually allows some rutting to occur over the

design life, as ruts will not necessarily impair service. Obviously, ruts are not acceptable in

permanent roadways.

For temporary roads, our design basically uses geosynthetics for the construction and traffic

support of the roadway section allowing for a specific tolerable amount of rutting.

Recommended design procedures for temporary roads are presented in Section 6 for

geogrids. Approaches for using geogrids in permanent roads for stabilization and base

reinforcement are covered in Section 7. Design for each application is based on the

function(s) of the geosynthetic and the properties required to perform the intended functions

as covered in the following sections.