What is the difference between Bridge and Culvert?

What is the difference between Bridge and Culvert?

Bridges and culverts are vital components of our civilization's infrastructure. Both provide conveyance, usually over rushing water, and are frequently confused with one another. However, several characteristics such as length, purpose, design complexity, building components, and structure distinguish bridges and culverts.

Bridge:

A bridge is a structure that carries a roadway or railway across a physical obstacle such as a river, lake, or another road or railway. A bridge is a drainage structure that provides a communication path for carrying road or railway traffic across an obstacle or depression, with or without water. Bridges are construed at a height more than 20 feet over the obstruction.

The communication route might be a railway, roadway, cycle track, footpath, or a mix of the two, while the blockage could be a river, stream, valley, channel, road, railway track, etc.

Bridges can be divided into three main categories depending on the span length:

Minor Bridge: A minor bridge is one that has a total span length of more than 6m but less than 60m.

Major Bridge: A major bridge is the one that has a total span length more than 60m.

Long Span Bridge: Long span bridge is the one that has span length more than 120m.

Bridge

Culvert:

A culvert is a tunnel structure that allows water to flow beneath a road or railway. Culverts can also be used to drain water or bridge a gap over a physical impediment. A culvert is a tunnel like structure with a total length of 6 m or less between the faces of abutments. Culvert are constructed at less than 20 feet over the obstruction.

Culverts are drainage structures that are used on roads, streets, and railways to divert unwanted water from the road. Culverts are long-term drainage structures that are typically built over minor streams or canals.

Culverts and bridges were created during road building to allow water to flow beneath the road, protecting both the road and the communities.

Culvert

Factors:

Culverts are categorized according to specifications based on their load capacities, water flow capacity, life spans, and bedding and backfill installation requirements. The continued operation of a culvert without failure is dependent on adequate design and engineering considerations for load, hydraulic flow, surrounding soil analysis, backfill and bedding compaction, and erosion prevention. Inadequate load support can cause material collapse or failure in poorly built backfill support surrounding culverts.

Purpose:

Culverts must also be appropriately sized and installed, as well as protected against erosion and scrub. The goal of culvert construction is to reduce flooding, minimize erosion, and create run-off paths. Culverts are therefore found beneath roadways or railways. Culverts should be installed perpendicular to the road. However, the construction of a separate embankment is not required. The culvert should be placed such that water movement is simple. Effective culverts allow water and wildlife to pass freely. When culverts are overly narrow or improperly built, they can disrupt the natural flow of water upstream. Culvert failures can occur for a variety of reasons, including maintenance, environmental, and installation failures, functional or process failures related to capacity and volume, causing soil erosion around or beneath them, and structural or material failures that cause culverts to fail due to collapse or corrosion of the materials from which they are made.

Failures:

There are many different reasons why culverts can fail, including maintenance, environmental, and installation issues, functional or process issues related to capacity and volume that cause the soil around or beneath them to erode, and structural or material issues that result in culverts failing due to collapse or corrosion of the materials used to construct them.

If the failure is unexpected and catastrophic, it may cause harm or even death. Unexpected changes to the environment or poorly built and engineered culvert crossing sites frequently result in design parameters being exceeded and cause sudden road collapses. Over time, soil around culverts that are too small for the flow of water will be eroded. This might result in an abrupt collapse during moderate-sized rain events. Accidents resulting from culvert failure can also happen if an inadequately sized culvert is overwhelmed by a flood event and the road or railway above it is disrupted.

Precautions:

To prevent erosion and control the velocity of flow, the upstream and downstream show be provided with giant rocks or large stones which is called riprap. The purpose of riprap is to dissipate the energy. Large stones act as energy dissipaters. If the energy of water leaving a culvert is not reduced, it is very likely to be erosive. The dissipaters reduces the velocity, making the channel sides less likely to be washed away. There are numerous types of dissipaters, but a large stone is a straightforward approach. Without rip rap overflowing water could erode and cause it to eventually collapse.

Riprap