Home > Technology > Metal Culvert and Drainage Installation

5 guidelines for metal culvert and drainage installation

This article provides detailed information for the installation of corrugated metal pipe as culverts or storm water sewers. And to achieve long term performance, it also provides the necessary considerations for proper design.

For a typical pipe installation either as culvert or drainage, several points should be given attention to. Location is the first factor which will determines the smooth operation of succeeding processes. Excavation of embankment or trench is the place where the pipe installed. How to maintain an open trench safe is the vital. Foundation, stable and uniform, has a close relationship with the performance and life span of the pipe. Backfill combined with pipe will create great strength to withstand huge load.

Before installation, recheck the planned alignment and grade of the pipe in connection with the topography of the site.


Embankment condition
Remove the topsoil, much and organic matter and prepare a uniform and stable foundation at the proper elevation and grade.

Trench condition
Trenches are the most installation positions of storm sewers. There are three phases (excavation, pipe installation, and backfilling) of construction in a trench, which are should be planned in advance. Some general guidelines to be followed:
Trench excavation
Trench excavation normally runs in the upgrade direction. Along the upgrade direction, the trenching equipment is efficient and pipe sections are easily joined. When excavated soil is used as backfill, it should be stockpiled at a safe distance from the edge of the trench. If trench walls are not supported by, the safety distance should not be less than one-half the depth of the trench. If the trench walls are protected, the safety distance still should be maintained, varying with soil types.

Attentions to an open trench
Cares should be given when operations are near the open trench. If the equipment is too close to the trench, equipment weight and vibration will collapse the trench walls. To eliminate accidents and losses to open trench, the following procedures should be followed:
Start excavation only when the installation of corrugated pipe can follow at the same time; Support trench walls to remain their stability throughout the construction period;

Trench width and shape
In a general rule, the trench width should be wider than the pipe, about 12 to 48 inches (300 to 1200 mm). This distance is suitable for typical backfill. Lesser space is required when slurries and other backfill materials are used which don’t need mechanical compaction.

Corrugated steel sewer structures should be placed on a stable, uniform foundation to maximize its performance and service life.

For corrugated steel pipe, the excellent foundation is by excavating to a flat surface and then carefully compact the fill under the haunches of the pipe. Flat foundation is suitable for corrugated pipes except for pipe-arches and horizontal ellipses.

All pipes should be placed on stable or fine granular foundation. Poor foundations, such as sod, frozen earth or a bed containing boulders or rock, are not suitable for pipe installation, for they cannot bear enough strength. Otherwise, it should stabilize the poor foundation first.

End treatment
End treatments of corrugated metal culverts through the embankment are often designed as square ends, which are adaptable to road widening projects. Flared end sections can be directly bolted to the factory fabricated pipe. When specified, ends of corrugated steel structures can beveled or skewed to match the embankment slop.

Proper backfill is a determining factor of loading of any type of metal culverts. To reach maximum strength and prevent washing out, the backfill should be made of good material, properly placed, and appropriately compacted.

Backfill material
Granular material containing a small amount of silt or clay creates a dense and stable fill. Rocks and hard earth clods larger than 3 inches in size are not available.

Placing the backfill
Embankment installations are often backfilled after the entire structure, or at least a major part of it, is assembled. For trench installations, backfill must follow as closely behind the excavation and assembly stages as possible.

If you need to consult the price, please contact the business department by E-mail:


When you contact us, please provide your detail requirements.
That will help us give you a valid quotation.