Biaxial Geogrids,made in Polypropylene(PP)with their square apertures,high tensile strength and optimised geometry of nodes and ribs make them equal to any other similar material. PP Biaxial Geogrids lies mainly in confining soil and increasing its shearing resistance by a process of interlocking between the square ribs and the soil.The load dispersal effect from the interlocking mechanism is highly effective and can reduce sub-base thickness and construction cost.
Geogrid for Subbase of Road Construction method:
(1) Clearing the surface
Remove weeds, trees and other debris harmful to the stability of the embankment within the scope of the subgrade. For the surface ponding or pond section, the water shall be drained first, the silt shall be removed, and the qualified earthwork shall be used for backfilling and compaction.
(2) Compaction of original surface
The site shall be leveled and the original surface shall be compacted with impact roller. The specific compaction scheme shall be implemented according to the construction scheme of subgrade impact rolling.
(3) Geogrid laying in the bottom layer
The geogrid is laid in full width within the scope of subgrade. Bamboo piles (or wooden piles) are used to mark the scope of geogrid laying, and then laying. The layer of geogrid shall be flat and straight; the width of both sides shall be the same as that of subgrade. There shall be no hard protrusions such as flake stones. The joint method is adopted for connection, and the two adjacent geogrids are jointed with interwoven high-strength polypropylene tape; or lap joint method is adopted, with the lap width not less than 20cm and fixed with "U" shaped nails.
(4) Earthwork filling
After the geogrid is laid, fill the subgrade. In order to avoid certain damage to the geogrid caused by rolling or turning around of transport vehicles, the method of rolling filling can be used for earthwork filling. The thickness of earthwork filling shall be based on the maximum loose paving thickness of soil: the earthwork embankment shall not exceed 30cm, and the rockfill embankment shall not exceed 50cm. Bulldozer leveling, roller rolling, earth filling and rolling shall meet the requirements of Subgrade Earthwork compaction specification.
(5) Laying of upper geogrid
After the earthwork filling and rolling is qualified, the upper layer geogrid shall be laid. The laying requirements and connection methods are the same as those of the bottom layer, but the width shall be consistent with the top width of the filling layer.
(6) Filling earthwork
After the upper geogrid is laid, another layer of soil shall be filled on it as soon as possible to prevent it from being damaged or lost. The earthwork of this layer shall be filled in strict accordance with the filling thickness and rolling requirements of Subgrade Earthwork, and the loose paving thickness shall not exceed 30cm. The construction technology and construction method shall be carried out according to the subgrade earthwork filling scheme.
