Plastic culvert pipes mainly include high-density polyethylene (HDPE) spiral reinforced pipes, steel-reinforced polyethylene (PE) spiral corrugated pipes (MRP), glass fiber reinforced sand-filled pipes (FRPM) and other types. Plastic culvert pipes with a diameter of 24 inches (about 610mm) are widely used in small and medium-sized drainage, highway culverts and municipal engineering. Its core advantages include:
Lightweight and high strength: Compared with concrete pipes, plastic culverts are light in weight (such as HDPE pipe density of about 0.95g/cm³), easy to transport and install, and can achieve SN8-SN16 ring stiffness through enhanced structures (such as steel belts and glass fibers), adapting to high fill and dynamic loads.
Corrosion resistance: Suitable for acidic and alkaline soils, saline areas and sewage environments, with a service life of more than 50 years, especially suitable for coastal or industrial areas.
Flexible structure: It can adapt to uneven foundation settlement and reduce structural damage in frozen soil and soft soil areas.
1. Foundation treatment
Use gravel or coarse sand cushion layer with a thickness of ≥30cm and a compaction degree of ≥95% after tamping.
In areas with collapsible loess or expansive soil, it is necessary to add waterproof geotextiles and strengthen drainage design.
2. Pipeline connection
Socket-and-spigot electric fusion connection: a common method for HDPE pipes, with good sealing and suitable for high water pressure scenarios.
Flange or bolt connection: steel-reinforced PE pipes or fiberglass pipes are mostly used, and attention should be paid to bolt corrosion protection (such as hot-dip galvanizing).
3. Backfill control
The wedge area on the side of the pipe is backfilled with coarse sand using the "watertight method" and manually compacted to the groove on the pipe wall.
Heavy machinery rolling is prohibited within 50cm of the top of the pipe, and the backfill is symmetrical in layers (20cm per layer), with a compaction degree of ≥96%.
Highway culverts: Suitable for sections with fill height ≤10m, especially in frozen soil and soft soil areas, it can replace concrete culverts.
Coal mining subsidence area: Steel belt reinforced HDPE pipes have strong anti-deformation ability and can be used for drainage projects in mining areas where the surface continues to sink.
Municipal drainage: FRP sand-filled pipes perform well in large water delivery projects in the Middle East and Africa, are resistant to high pressure (1.6MPa) and have a long service life.
Standardized production: The domestic "Corrugated Steel Pipe (Plate) for Highway Culvert Channel" (JT/T 791-2010) promotes the standardization of steel-plastic composite pipes.
Environmental protection needs: Reduce the amount of cement, sand and gravel, in line with the trend of green construction.
Large diameter innovation: The research and development direction extends to large-diameter plastic culverts above 2m, such as double-tube parallel design.
|
Indicator |
Plastic Culvert Pipe |
Concrete Pipe |
|
Construction Period |
Over 50% shorter |
Longer (requires curing) |
|
Lifespan |
Over 50 years |
30–50 years |
|
Total Cost |
Lower when span > 4m |
Lower cost for small spans |
24-inch plastic culvert pipe is gradually replacing traditional materials due to its advantages such as light weight, corrosion resistance and convenient construction. In the future, it is necessary to further optimize the connection technology and long-term durability monitoring standards of large-diameter pipes to expand their application in high-end scenarios such as high-speed rail and water conservancy.
