The direction of geogrid laying is perpendicular to the middle line of roadbed.
1. Preparations for laying:
Foundation treatment: First of all, the lower layer is leveled and compacted, requiring the smoothness not to exceed 15_, the compactness meets the design requirements, and the surface is strictly forbidden to have hard protrusions such as gravel and block stone.
Laying environment: outdoor temperature above 5 C, wind force below grade 4, no rain or snow. (Except for environmental or special requirements)
2. Laying and lapping methods:
Geotechnical grilles should be laid on the flattened lower deck according to the design width. When spreading, they should be straightened and smoothly, close to the lower deck, without distortion, folding or overlap. The overlap should be fixed with U-shaped nails or connectors.
When the geogrid is laid, the direction of the main strength of the reinforcement is perpendicular to the axis direction of the embankment, and each overlap length (longitudinal) is not less than 15, fixed with U-shaped nails or connectors, with a spacing of 1.0 m, a transverse overlap length of 30-90, and the overlap position is fixed with U-shaped nails or nylon ropes.
3. Quality inspection after laying and lapping:
After the completion of the geogrid laying, self-inspection should be carried out first.
4. backfill:
When geogrid materials are laid in place, fillers should be filled in time so as not to be exposed to direct sunlight for too long. Generally, the interval time does not exceed 48H.
Filling requirements: The maximum diameter of embankment filling materials within 8 of geogrid layer should not be greater than 6 and the first layer of geogrid filling pavement should be compacted by light bulldozer or front loader along the axis direction of embankment, and the compaction thickness should be greater than 60.