Construction method of unidirectional tensile geogrid
The laying of the Uniaxial geogrid should be carried out according to the design requirements, and the bottom of the ditch and the roadbed should be inspected and accepted before laying, and the filler should be laid after passing the test. Geogrid is a high-strength geosynthetic material made of plastic bags (or steel wire) and steel bars, formed by special equipment and criss-cross welded. It is suitable for strengthening weak foundations and leak-proof and waterproof layers in large-scale projects such as dams and tunnels; it is also convenient for soft foundation treatment in road and railway construction; it can also be used as reinforced retaining walls, interlocking structures and other fields. When laying, the grid should be laid flat on the leveled site, tightened so that the grid is close to the surface of the road (foundation), and an overlapping width of about 15cm is left for later use. Center two adjacent plastic bags for connection.
When laying the Uniaxial steel-plastic rib film, first divide a Uniaxial plastic bag into two bundles along the horizontal axis, and fix them on the fixed longitudinal horizontal ribs respectively. Insert the transverse part on the other longitudinal horizontal rib into the transverse part fixed on the longitudinal horizontal rib, and then use U-shaped nails to pass through from both ends.
When used on roadbed and road surface, the construction method is as follows:
For the old asphalt concrete pavement and old cement concrete pavement, make a 20mm-30mm thick leveling layer, and use a vacuum truck or a sprinkler to ensure that the road surface is clean.
Spray AH-70 or AH-90 heavy oil hot asphalt, the dosage should be 0.3kg-0.4kg/m2.
Use the special paving vehicle provided by our group to lay the self-adhesive fiberglass grating, and the laying should be smooth and tight.
The horizontal lap length should be 50mm-100mm, the longitudinal lap length should be 150mm-200mm, and the overlapping direction of the lap should be consistent with the running direction of the asphalt paver.
Use rubber-tyred road rollers for rolling (rubber-tyred road rollers need to have sprinklers).
When used in reinforced soil retaining walls, the construction method is as follows:
Set up the foundation and carry out the construction according to the designed wall system. When the prefabricated reinforced concrete panel is selected, it is usually supported on the prefabricated concrete foundation with a thickness of 12-15cm. Its width is not more than 30cm, its thickness is not less than 20cm, and its buried depth is not less than 60cm to prevent the foundation from being affected by frost heave.
Level the wall foundation, excavate and level it according to the design requirements. The soft soil needs to be compacted or replaced, and compacted to the required density, it should be slightly beyond the scope of the wall.
When the reinforcement is laid, the main strength direction of the reinforcement should be perpendicular to the wall and fixed with pins.
Fill the wall with mechanical filling, and the distance between the wheel and the reinforcement should be kept at least 15cm. After compaction, the thickness of a layer of soil is about 20-15cm.
When the wall is constructed, the wall should be wrapped with geotextiles to prevent the leakage of filling soil.
Uniaxially stretched geogrid is a kind of high molecular polymer as the main raw material, adding certain anti-ultraviolet and anti-aging additives, after unidirectional stretching, the original scattered chain molecules are rearranged into a linear state, It is a high-strength geotechnical material that is extruded into a thin plate, punched into a regular mesh, and then stretched longitudinally. In this process, the polymer is made into an oriented linear state and forms an oblong network-like integral structure with uniform distribution and high node strength. Because of its high tensile strength, good creep performance, convenient construction and low price, it has been widely used.