How much do you know about geogrids? ( 5 )
How much do you know about geogrids? (5)
The grille is a very popular geotechnical material, which is widely used in road engineering, municipal engineering, geotechnical engineering and so on. There are many kinds of grilles. Do you know their advantages, uses and construction methods? Here, we will introduce you one by one.Classification of Geogrids.
- Construction site: It is required to be compacted flat, horizontal and clear sharp protuberances.
- Geogrid Laying:
- In order to ensure the width of roadbed, each side of roadbed is widened by 0.5m. After leveling the basement soil, it is compacted by 12T vibratory roller, 25T tyre roller or 2.5T tamping hammer. The uneven areas are leveled manually (without thin layer patching).
- Paving 0.3m thick medium (coarse) sand, manual with mechanical leveling, 25T vibratory roller static pressure twice.
- When laying geogrids, the bottom surface of geogrids should be flat and compact. Generally, they should be laid flat, straightened, not curled or twisted. Two adjacent geogrids need to be overlapped by 0.2m, and the overlapping part of geogrids should be connected with 8 wires every 1 m along the lateral direction of subgrade. On the laid grids, U-nails are used to fix the ground every 1.5-2m.
- After the first layer of geogrid is laid, the second layer of 0.2m thick medium (coarse) sand is filled. The method is to fill 0.1M in the range of 2 meters on both sides of the roadbed, then fold the first layer of Geogrid and fill 0.1m thick (coarse) sand. After the second layer of medium (coarse) sand is leveled, horizontal measurement is needed to prevent uneven filling thickness. After the second layer is leveled, 25T vibratory roller is used to roll it twice.
- The construction method of the second layer geogrid is the same as that of the first layer. Finally, 0.3 m of medium (coarse) sand is filled. The filling method is the same as that of the first layer. After two times of static pressing with 25T roller. In this way, the reinforcement of the subgrade foundation will be completed.