Correct Answer - Option 4 : Muck excavation
Explanation:
Earthwork or excavation involves the movement of a portion of the earth’s surface from one location to another and, in its new position, the creation of the desired shape and physical condition. Occasionally, the material moved is disposed of as spoil.
Types of Excavation
A common method of classifying excavation is by type of excavated material:
1. Muck excavation
It is the removal of material that contains an excessive amount of water and undesirable soil. Its consistency is determined by the percentage of water contained. Because of the lack of stability under load, muck seldom can be used in an embankment.
2. Earth excavation
It is the removal of the layer of soil immediately under the topsoil and on top of the rock. Used to construct embankments and foundations, earth usually is easy to move with scrapers or other types of earth moving equipment.
3. Rock excavation
It is the removal of a formation that cannot be excavated without drilling and blasting.
4. Topsoil excavation
It is the removal of the exposed layer of the earth’s surface, including vegetation. Since the topsoil, or mantle soil, supports the growth of trees and other vegetation, this layer contains more moisture than that underneath.
5. Unclassified excavation
It is the removal of any combination of topsoil, earth, rock, and muck. Contracting agencies frequently use this classification. It means that earth moving must be done without regard to the materials encountered.
