What Is an Embankment?
An embankment is an artificial barrier that typically is used to hold back water or to support a roadway, railway, or canal. These man-made mounds mainly consist of stones, rocks, and earth. Most have sloping sides, much like small hills. Generally, embankments are longer then they are tall.
Typically, there are two general purposes served by building an embankment. One purpose is to hold back water in order to prevent flooding from seas, lakes, or rivers onto adjacent land. These typically strong barriers provide protection to lower-lying grounds by acting as a levee, as well. An embankment helps to confine the movement of water by allowing it to flow faster and higher without overflowing.
The second purpose of an embankment is to support transportation. A transportation embankment usually is used to support a roadway, canal or railway by keeping land flat or straight and uninterrupted. It also may be used to support lowlands, such as valleys, that may need to be crossed. A transportation embankment is the opposite of transportation cutting, where a section of a mountain or hill is cut to make room for a road or railway.
Most embankments are built so as to be immune to surface erosion. Components by which they are made usually help to prevent deterioration. These hill-like structures are filled in a variety of ways. The makeup generally varies according to what the structure will be used for.
An embankment may be either earth- or rock-filled. An earth-filled barrier usually is the simpler of the two, consisting mainly of earth and natural materials. A rock-filled barrier generally is made up of more granular components, consisting mostly of large varieties of rocks, stones, and other fragmented particles. Rock-filled mounds usually are more ideal to cover wider areas.
Even though they are built to withstand intensity, embankments can become stressed. The stress of water can increase the depth of the embankment, therefore altering its durability. Prior to building an embankment, it usually is important to calculate the maximum stress level. This is necessary to ensure the break-level of the bank is not surpassed by its stress capacity.
Any misconfiguration when building an embankment could lead to overflowing. The overflowing of a water barrier, such as a levee, can lead to a disastrous situation. The massive flooding in New Orleans brought about by Hurricane Katrina in late August, 2005, was the result of failed levees. Such failures can happen when the water pressure caused by overflowing begins to erode the core structure of an embankment.
Written by Nat Robinson
