Plastic geogrid: it is a square or rectangular polymer mesh material formed by stretching. It can be divided into unidirectional stretching and biaxial stretching according to the different stretching directions when it is manufactured. It is a production line equipment for punching plastic geogrids on extruded polymer plates (mostly polypropylene or high-density polyethylene), and then carrying out directional stretching under heating conditions.

The unidirectional stretching grid is only made by stretching along the length of the plate, while the bidirectional stretching grid is made by stretching the unidirectional stretching grid in the direction perpendicular to its length. Convenient and fast construction, short period and low cost: the steel plastic geogrid is easy to be laid, overlapped, positioned and leveled, avoiding overlapping and crossing, which can effectively shorten the project cycle and save 10%-50% of the project cost.

Firstly, the subgrade slope line shall be set out accurately. In order to ensure the subgrade width, each side shall be widened by 0.5m. After leveling the dried foundation soil, it shall be tamped with 12t vibratory roller, 25t tire roller or 2.5t rammer. The uneven places shall be leveled manually (thin-layer pasting and leveling are not required).

The geogrid production line equipment shall be paved with 0.3m thick medium (coarse) sand. After manual and mechanical leveling, the 25t vibratory roller shall be statically pressed twice. When laying the geogrid, the bottom surface shall be flat and dense. Generally, the geogrid shall be laid flat and straight without curling or kinking. The two adjacent geogrids shall be overlapped for 0.2m, and the overlapped part of the geogrid shall be connected with 8 iron wire every 1m along the transverse direction of the subgrade. The laid geogrid shall be fixed on the ground with U-nails every 1.5-2m. After the first layer of geogrid is paved, the second layer of 0.2m thick medium (coarse) sand shall be filled,

Filtration (inverted filtration) when the water flows from the fine soil layer to the coarse soil layer, the polyester staple fiber needled geotextile with good air permeability and water permeability is used to make the water flow through, and effectively intercept the soil particles, fine sand, small stones, etc., so as to maintain the stability of the water and soil engineering.