Types of Culverts

Introduction

While driving through the road to reach your destination, you come across a number of infrastructures be it on the urban road or the outskirts of the town. Some of the infrastructures are built to drive you safely, give information and cross the water bodies and terrain. There are many infrastructures which cross the water bodies. What are bridges, culverts, causeways, etc? In this article, we will focus on culverts.

What is Culvert?

The culvert is a type of civil engineering infrastructure that allows water to flow freely across a stream, channel, or gully without being disrupted. They are built in accordance with the discharge flow and site circumstances.

Culverts are mainly constructed to cross the water bodies, and channel out the water.

Materials Used for Culvert Construction

The materials for culverts are listed below: –

1. Concrete
2. Steel
3. Aluminium
4. Plastic
5. HDPE pipe

The most common type is concrete due to its durability. Concrete culverts may be reinforced or none reinforced. They may be cast in situ or directly install pre-cast culverts.

Types of Culverts

The types of culverts are as follows: –

1. Pipe Culvert
2. Pipe Arch Culvert
3. Box Culvert
4. Arch Culvert
5. Bridge Culvert

Pipe Culvert

Pipe culverts are constructed using concrete pipes. The concrete pipe is usually reinforced with a reinforcement bar and is only allowed for this purpose. The limitation of the pipe culverts is the movement of the discharge is limited. This type of structure is suitable for having a continuous flow of discharge. For example, Strome water drain and channelling out the roadside drain.

Pipe Arch Culvert

Pipe arch culverts are a structure made of a combination of one or more pipe arches. The bottom arches provide a way for the water to flow. Pipe arch culverts can be of single or multiple pipe arches. These are arches made from pipes that could be manufactured from concrete or steel.

They are suitable for large water flows and the flow should be continuous and stable.

Arch Culvert

As the name suggests, this is similar to pipe arch culverts. However, it does not make use of pipes or pipes. The arch is single or multiple depending upon the flow of the water through the channel. This is the oldest type of culvert ever used by human civilization.

The artificial flooring is provided for the flow of water through it. The flooring may be reinforced or unreinforced concrete.

Box Culvert

A box culverts consist of an RCC box of square or rectangular opening with the span generally restricted to 4m. The top of the box culverts may be at the road level or at a depth below the road level of the road in an embankment. A single box culvert becomes uneconomical when the design discharge is considerable due to the thickness of the slab and walls. In such cases, more than one box is built side-by-side monolithically.

Box culvert is only applicable when the discharge through the drain or channel is small and the bearing capacity of soil is low. Hence, the bottom slab is provided and also it acts as artificial flooring for the flow of water.

Components of Box Culvert

The structural design demands the following components for the box culverts: –

• Top slab: It is the top element of the structure with the reinforced concrete slab. This element provides the construction of roads and walkways. Normally asphalt concrete is placed on the top of the slab to make the continuation of the road. Usually, the top slab is designed for bending and shear forces generated by applied loads.
• Side Walls: These are the walls that transfer the loads from the super-structure (top slab) to the sub-structure. They carry the vertical loads and bending moments induced by the top slab. They are placed at the two extreme ends top slab.
• Bottom Slab: It acts like a foundation or sub-structure for the box culverts. It is designed for bending and shear forces due to the applied loads.

Bridge Culvert

The bridge culvert is a development of box culverts. Unlike box culverts, they do not have a bottom slab. For a culvert of this type, a foundation is provided under the ground surface. They are similar to bridges and rectangular in shape. Thus, the name bridge culvert is given to it.

Bridge culverts are provided on canals or rivers and are also used as road bridges for vehicles. Like all other types of culverts, box culverts can also be built single or a series of culverts and pavement surface is laid on top of the structure.

Advantages of Culverts

1. It helps in preventing flooding.
2. The flow of discharge is not disturbed.
3. Erosion is prevented due to the continuous flow of water through the canal.
4. Offers ease of crossing water bodies for both vehicles and commuters.

FAQs

Read also:

• Difference Between Bridge and Culvert