What is the meaning of earthfill dam?

earthfill dam, also called earth dam or embankment dam, dam built up by compacting successive layers of earth, using the most impervious materials to form a core and placing more permeable substances on the upstream and downstream sides.

What is the purpose of a embankment dam?

Dams constructed of soil, of rock, or of a combination of soil and rock are called embankment dams. Embankment dams are most economical where the materials at the dam site can be used to construct the embankment with little or no processing.

What are the types of embankment dams?

Types. Embankment dams come in two types: the earth-filled dam (also called an earthen dam or terrain dam) made of compacted earth, and the rock-filled dam. A cross-section of an embankment dam shows a shape like a bank, or hill.

What is zoned embankment?

Zoned type dam : • A zoned embankment dam is composed of more than one kind of material. This is most common type of a rolled fill dam in which a central impervious core is flanked by zones of materials considerably more pervious. • The pervious zones enclose, support and protect the impervious core.

What is embankment in road construction?

The earthen material, which is get laid and compacted to raise the grade line of a proposed highway or railway above the original ground level of the existing ground, is called embankment.

What is the purpose of a toe drain?

The purpose of the toe drain is to collect water seepage in the earthen dam and safely convey it to the pond outfall (8” toe drain outlet pipes can be seen on either side of the large rectangular spillway pipes in the photo below). Toe drains perform an important function in maintaining a safe and secure dam.

What does the word embankments mean?

Definition of embankment 1 : a raised structure (as of earth or gravel) used especially to hold back water or to carry a roadway. 2 : the action of embanking.

What is casing embankment?

Casing: The casing is the component of an embankment dam that protects the inner core. The upstream and downstream slopes of a casing have to be decided based on the type of dam, height, availability of material, and the condition of the foundation. A flatter slope is built in case of low permeability material.

What is zoned embankment type earthen dam?

Explanation: Zoned earth dam is also called a non-homogenous or heterogeneous earth dam and it is suitable on shallow pervious foundations. This dam is widely constructed and the materials of the zone are selected depending upon the availabilities.

What is embankment and subgrade?

The subgrade is that portion of a road- way immediately below the surface, base or sub-base. An embankment is that portion of a roadway which has been built above the original ground by depositing material obtained from cuts or borrow pits. The upper layer of an embankment is also the subgrade.

What is the difference between backfill and embankment?

As nouns the difference between embankment and backfill is that embankment is a long artificial mound of earth and stone, built to hold back water, for protection or to support a road while backfill is the material that has been used to refill an excavation.

How are earthfill embankment dams made?

An earthfill embankment dam is made by building a foundation wall that is embedded into the rock below the dam to prevent water flowing beneath it and then creating a core of impermeable clay on top of this (Figure 8.3 ). Above this the remaining structure is built from earth, normally from the surrounding area.

What is another name for a rockfill dam?

Alternative Titles: earth dam, embankment dam, rock-fill dam. Earthfill dam, also called Earth Dam, or Embankment Dam, dam built up by compacting successive layers of earth, using the most impervious materials to form a core and placing more permeable substances on the upstream and downstream sides.

What are the two types of embankment dams?

The construction of a spillway that will release water from the reservoir when the water level rises too high is necessary as embankment dams are vulnerable to erosion caused by overflow of water. The two main types of these dams are earthfill embankment dams and rockfill embankment dams.

Which is the largest earth filled dam in the world?

It is the largest earth-filled dam in the world. An embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil, sand, clay, or rock. It has a semi-pervious waterproof natural covering for its surface and a dense, impervious core.