What Is Earthen Dam?
The dam which is constructed fulfilled by the earth is known as the earthen dam. The earthen dam is constructed by different layers of soil.
The layers of the soil of the earthen dam are then compacted by sheep’s foot rollers, tamping rollers, heavy pneumatic tired rollers, earth-hauling equipment, or vibratory rollers.
The earthen dam is constructed as a barrier that resists water or underground streams. These earthen dams are constructed not only for protection from floods, but also provides water for various needs to include human consumption, irrigation, industrial use, navigability, and aquaculture.
The earthen dam is constructed nearly trapezoidal or trapezoidal cross-section. There are many sizes of earthen dams is constructed. But the size of the dams depends on the requirements.
As for the high earthen dam, the height of the dam is greater than 100 m. As for the medium earthen dam, the height of the dam is lies between 50 m to 100 m. And for the small earthen dam, the height of the dam is lower than 50 m.
Types of Earthen Dam
The earthen dam classifying three types that’s are below –
- Homogeneous Embankment Earthen Dam.
- Zone embankment Earthen Dam.
- Diaphragm Earthen Dam.
1. Homogeneous Embankment Type Earthen Dam
This type of earthen dam is very economical and simple. Because the earthen dam consists of a single material. And this type of earthen dam is also throughout homogeneous.
On the upstream face of the earthen dam sometimes, a blanket of moderately watertight material may be placed. In an earthen dam when just one material is economically or locally available then a simply homogeneous section is used.
2. Zone Type Earthen Dam
The zone-type earthen dams are widely constructed. The material used for the zone-type earthen dam is depending upon their availabilities.
If it shrinks and swells too much, may not make the best core with the clay, despite it being highly impervious. Because of this, sometimes the clay is mixed with fine sand or fine gravel to make an impervious layer for the dam.
As the satisfactory central core materials sometimes silts or silty clays may be used. On the outer shell for freely draining the materials, such as coarse sands and gravels are generally used.
Between the outer and inner zone of the earthen dam, transition filters are provided. From one zone to the other, where the abrupt change of permeability on there the transition filters are always provided.
3. Diaphragm Earthen Dam
The diaphragm earthen dam is surrounded by earth or rocks thin impervious core. This impervious core is made of concrete, impervious oils, timber, steel, or any other material.
To prevent seepage through the dam the impervious core act as a barrier. The diaphragm earthen dam is placed either at the upstream face as a layer or the center as a central vertical core.
To avoid excessive under-seepage through the existing previous foundations in the diaphragm embankment must also be tied to the bedrock or very impervious foundation material.
On depending the thickness of the core the diaphragm embankments are differentiated from zoned embankments.
Failure of Earthen Dam
The earthen dam is less rigid so it has more chance of failure. The classification of the earthen dam is below-
- Hydraulic Failures.
- Seepage Failures.
- Structural Failures.
1. Hydraulic Failures
The hydraulic failure occurs for the below reasons.
1.1. By Overtopping
if the spillway gates are not properly operated or if the design flood is underestimated then the water may overtop the dam.
1.2. Erosion of Upstream Face
sometimes, cause the slip of the upstream slope and try to notch out the soil from the upstream face and may even due to the winds the waves developed near the topwater surface.
1.3. Cracking Due to Frost Action
The soil with dangerous seepage and consequent, the failure of the dam may cause frost in the upper portion.
2. Seepage Failures
The seepage failure occurs for the below reasons.
- Ordinarily, it does not produce any harm by the Controlled seepage or limited uniform seepage is inevitable in all earth dams.
- The subsequent failure of the dam uncontrolled or concentrate seepage through the dam body or its foundation may lead to piping or coughing.
3. Structural Failures
Causing slides the Structural failures are generally caused by shear failures. The structural failure occurs for the below reasons.
The entire dam may slide over the foundation When the foundation of the earth dams are made of, such as fine silt, soft clay, soft soils, etc.
Methods of Construction of Earth Dam
- The method of an earthen dam constructed fulfilled by the earth is known as the earthen dam.
- The earthen dam is constructed by different layers of soil.
- The layers of the soil of the earthen dam are then compacted by sheep’s foot rollers, tamping rollers, heavy pneumatic tired rollers, earth-hauling equipment, or vibratory rollers.
- The earthen dam is constructed as a barrier that resists water or underground streams.
- These earthen dams are constructed not only for protection from floods, but also provides water for various needs to include human consumption, irrigation, industrial use, navigability, and aquaculture
- The earthen dam is constructed nearly trapezoidal or trapezoidal cross-section.
- There are many sizes of earthen dams is constructed. But the size of the dams depends on the requirements.
- As for the high earthen dam, the height of the dam is greater than 100m.
- As for the medium earthen dam, the height of the dam is lies between 50m to 100m.
- And for the small earthen dam, the height of the dam is lower than 50m.
Application of Earthen Dam
There have been many applications of the earthen dam that’s are below.
- The earthen dam is constructed to apply as a barrier that resists water or underground streams.
- These earthen dams are constructed not only for protection from floods, but also applied to for provides water for various needs to include human consumption, irrigation, industrial use, navigability, and aquaculture.
- When we need to make an economical structure then we need to apply the earthen dam because In an earthen dam just one material is economically or locally available then a simply homogeneous section is applied.
- In the earthen dam the hydropower is applied to generate the electricity.
- For structural reasons, earth dams are suited to the sites where a masonry dam cannot be applied.
- The earthen dam is applied to either stop or slow the amount of water in a river.
Advantage of Earthen Dam
- The advantage of the earthen dam is the material of the earthen dam like soil can easily available.
- Another advantage of the earthen dam that’s is can easily handle by the hands.
- For structural reasons, earth dams are suited to the sites where a masonry dam cannot be used.
- Another advantage of the earthen dam is it is a lesser cost than normal masonry walls.
- The advantage of the earthen dam is it can slow or stop the amount of water in a river.
Disadvantage of Earthen Dam
- The disadvantages of the earthen dam are the non-availability of the materials at the dams site.
- Another disadvantage of the earthen dam is as compared to a good concrete dam it has a greater maintenance cost.
- For spillways, the earthen dam is none suitable, this is an important disadvantage of an earthen dam.
- The disadvantages of the earthen dam are it is a none rigid material so it can destroy easily when more stress develops on the dam.
Uses of Earthen Dam
There have been many uses of the earthen dam that’s are below.
- The earthen dam is constructed to use as a barrier that resists water or underground streams.
- These earthen dams are constructed not only for protection from floods, but also used for provides water for various needs to include human consumption, irrigation, industrial use, navigability, and aquaculture.
- When we need to make an economical structure then we used the earthen dam because In an earthen dam just one material is economically or locally available then a simply homogeneous section is used.
- For structural reasons, earth dams are suited to the sites where a masonry dam cannot be used.
- To either stop or slow the amount of water in a river the earthen dam is used.
- The earthen dam is a good choice for sites with wide valleys.
- In the earthen dam, by using hydropower is often used in conjunction with dams to generate electricity.
FAQs (Frequently Asked Questions) that could complement your article on earthen dams:
What is an earthen dam?
An earthen dam is a structure built primarily using compacted earth or soil layers to create a barrier that holds back water.
What are the types of earthen dams?
Earthen dams are classified into three main types: homogeneous embankment, zone embankment, and diaphragm dams, each differing in construction methods and materials used.
What are the main reasons for constructing earthen dams?
Earthen dams are built to control floods, provide water for irrigation, human consumption, industrial use, aquaculture, and to generate hydropower.
How are earthen dams constructed?
Earthen dams are constructed by layering and compacting soil using heavy rollers and earth-moving equipment to ensure stability and water resistance.
What are the potential failures of earthen dams?
Earthen dams can fail due to hydraulic issues (overtopping, erosion), seepage, or structural failures (such as slides or collapses).
What advantages do earthen dams offer compared to other types of dams?
Advantages include lower construction costs, suitability for sites where rigid structures like concrete dams may not be feasible, and the availability of construction materials.
What are the disadvantages of earthen dams?
Disadvantages include higher maintenance costs compared to concrete dams, limitations in using spillways, and susceptibility to damage under stress.
Where are earthen dams commonly used?
Earthen dams are commonly used in areas with accessible soil resources, wide valleys, and where economic construction is prioritized over other dam types.
How do earthen dams contribute to energy production?
Earthen dams often incorporate hydropower facilities to generate electricity, utilizing water flow controlled by the dam.
What are the environmental considerations associated with earthen dams?
Environmental impacts include habitat alteration, sedimentation, and effects on local hydrology, which are managed through careful design and planning.
