The inner shape of a trench drain has a significant influence on its hydraulic performance. The material from which this inner section is created also makes a difference; with smooth surfaces preferred over bumpy or rough concrete.
If trench drains are incorrectly designed, they will lack the ability to clear rainwater efficiently. When this happens, pavements are likely to cost developers in maintenance and repair. In our previous article, we described how the slope had a considerable impact on the performance of a trench drain’s hydraulics. In particular, we discussed how it helps determine the velocity of the liquid that flows through it.
Water travels downhill, and if the pavement cannot assist in this endeavour, then the drainage must be configured to provide the necessary falls, preferably by implementing a slope in the base of a trench run. Factory manufactured sloped channels enable sufficient drainage, while a stepped configuration isn’t as likely to have as great of an affect on a drain’s hydraulic performance.
In this article, we’re going to look at how the shape of a trench drain impacts hydraulic performance.
Hydraulic Properties of V Shaped Trench Drains
When considering hydraulic properties of trench drains, the ultimate piece of the puzzle is the internal shape of the drainage channel. Inspired by the shape of traditional egg (V) shaped sewers; ACO has transferred these benefits to its external drainage systems.
Egg shaped sewers have been used for many years, since as early as 19th century London. Also known as oval shaped sewers, at the time they were considered the best option for larger combined sewers. This particular design went on to be used for the sewers in Paris, and eventually in the United States too.
While V-shaped sewers and drains were originally inspired by their egg-shaped counterparts, their popularity is fundamentally due to two driving advantages:
- There are no corners for matter to collect.
- They possess excellent hydraulic properties.
ACO’s V-shaped Polycrete® Channels are the world’s most efficient surface drainage system. They ensure liquid velocity is optimised to allow efficient flow through the drainage system for up to 40 metres in a variety of widths and load classes.
The main benefit is that the fast liquid velocities promote a self-cleaning effect not only during times of heavy rainfall, but also when rainfall is light. Nevertheless, it’s not only the shape and slope which define the hydraulic performance of a drain – the materials used to construct it also play a vital role.
Trench Drain Materials
A smooth surface of a channel enables fluids to flow at their optimum speeds. Polymer concrete is an ideal material to use if the hydraulic performance of a trench drain is to reach its full potential.
Utilising this type of material makes channels much easier to clean as it doesn’t support biological (plant life) or bacterial growth (mould).
ACO has developed innovated drainage systems to cater to the needs of a constantly changing environment.
For more information on drainage theory, click here
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