Culverts are tunnel-like structures that are constructed under roadways, railways and other similar obstacles and are primarily designed to provide cross drainage and to allow water to flow through them. A single culvert or multiple culverts can be used under a given structure dependent on the size of the waterway and the desired level of flow through the passage.
Culverts can also be used in a number of other ways including passing cables (electrical or otherwise) through them, intakes and outtakes, service tunnels and utility trenches to name a few, making them one of the most useful structures in modern construction.
With the culvert systems typically enclosed entirely by soil or ground, it is essential that they are strong and durable meaning that they are often made out of concrete. Although considering that culverts so frequently vary in size and shape, other materials are also used to construct them such as steel, plastic and aluminium while they can also be reinforced or combined to form composite structures.
Pipe Culvert - these round-shaped structures commonly made of concrete or steel are a popular choice given their durability and capabilities to allow larger flows through effectively
Pipe-Arch Culvert – similar to the pipe culverts, these structures are also rounded in shape but allows water to flow through at the widest part of the culverts. This makes them particularly useful for natural flows, as things such as wildlife (fishes) or sewage easily pass through the channel without getting caught in the inlets at the bottom of the structure
Box Culvert – as the name suggests, these are rectangular in shape and generally constructed of reinforced concrete. This can increase the load capacity to pass above the culvert meaning their use can extend to provide bridges and crossings, whilst the shape also enables this design to commonly be used as its own passage for service vehicles etc.
Arch Culvert –these are like the pipe arch culverts, but with the addition of an artificial flooring at the bottom of the arch. They are often made out of concrete and are more commonly used in narrower pathways.