Geogrids can stabilize subgrades in several ways:
Lay it on the roadbed and backfill it with gravel or soil, which can reduce the bulk density of the roadbed and stabilize the roadbed.
Lay the geogrid on the subgrade and apply a load greater than 1.5 tons per square meter. When the bearing capacity under the subgrade meets the requirements, the subgrade in this area does not need to be reinforced.
The geogrid is laid directly on the subgrade, and the bearing capacity of the foundation must reach 30 tons/square meter, and it must be filled and compacted in layers.