Biaxial Fiberglass Gravel Driveway Geogrid

Biaxial Fiberglass Gravel Driveway Geogrid offered by China manufacturer Lianyi Group. Buy Biaxial Fiberglass Gravel Driveway Geogrid directly with low price and high quality.

When an aggregate layer is loaded by a vehicle wheel or dozer track, the aggregate tends to

move or shove laterally, as shown in Figure 2a, unless it is restrained by the subgrade or

geosynthetic reinforcement. Soft, weak subgrade soils provide very little lateral restraint, so

when the aggregate moves laterally, ruts develop on the aggregate surface and also in the

subgrade. A geogrid with good interlocking capabilities or geocomposiste with good

interlocking and frictional capabilities can provide tensile resistance to lateral aggregate

movement.

Another possible geosynthetic reinforcement mechanism is illustrated in Figure 2b. Using

the analogy of a wheel load to a footing, the geosynthetic reinforcement forces the potential

bearing capacity failure surface to follow an alternate higher strength path. This tends to

increase the bearing capacity of the subgrade soil.

A third possible geosynthetic reinforcement function is membrane-type support of wheel

loads, as shown conceptually in Figure 2c. In this case, the wheel load stresses must be great

enough to cause plastic deformation and ruts in the subgrade. If the geosynthetic has a

sufficiently high tensile modulus, tensile stresses will develop in the reinforcement, and the

vertical component of this membrane stress will help support the applied wheel loads. As

tensile stress within the geosynthetic cannot be developed without some elongation, wheel

path rutting (in excess of 4 in. {100 mm}) is required to develop membrane-type support.

Therefore, this mechanism is generally limited to temporary roads or the first aggregate lift in

permanent roadways.

A geosynthetic placed at the interface between the aggregate base course and the subgrade

also functions as a separator to prevent two dissimilar materials (subgrade soils and

aggregates) from intermixing. Geotextiles perform this function by preventing penetration of

the aggregate into the subgrade (localized bearing failures) and prevent intrusion of subgrade

soils up into the base course aggregate (Figure 3). Geogrids can also prevent aggregate

penetration into the subgrade, depending on the ability of the geogrid to confine and prevent

lateral displacement of the base/sub-base. However, the geogrid does not prevent intrusion

of subgrade soils up into the base/sub-base course, which must have a gradation that is

compatible with the subgrade based on standard geotechnical graded granular filer criteria

when using geogrids alone. Subgrade intrusion can also occur under long term dynamic

loading due to pumping and migration of fines, especially when open-graded base courses

are used. It only takes a small amount of fines to significantly affect the structural

characteristics of select granular aggregate (e.g., see Jornby and Hicks, 1986). Therefore,

separation is important to maintain the design thickness and the stability and load-carrying

capacity of the base course. Thus, when geogrids are used, the secondary function of

separation must also be considered.