Which technique of excavation is best for a sequential understanding of a site?
The sequential excavation method (SEM) is used for the construction of shallow mined tunnels that have ground conditions that are fully dry or have been effectively dewatered. The method is also known as the new Austrian tunneling method (NATM), as the idea for this method originated in Austria.
What is NATM technique?
The New Austrian tunneling method (NATM), also known as the sequential excavation method (SEM) or sprayed concrete lining method(SCL), is a method of modern tunnel design and construction employing sophisticated monitoring to optimize various wall reinforcement techniques based on the type of rock encountered as …
What means NATM?
NATM means “Not At The Moment.” This is the most common definition for NATM on Snapchat, WhatsApp, Facebook, Instagram, TikTok, and Twitter. NATM. Definition: Not At The Moment.
What is SPL in tunneling?
Speciality Product Line (SPL)
What is cut-and-cover tunnel?
Cut-and-cover is the oldest method of tunneling. The basic concept involves the digging of a trench, the construction of a tunnel, and then returning the surface to its original state. As such, it is a disruptive technique, but it is also usually the most economical construction method.
What is drift method of tunneling?
Drift Method: In this method after driving the drift, the drill holes are drilled all round the drift in the entire cross section of the tunnel, filled with explosives and ignited. The rock shatters, the muck removed and the tunnel expanded to the full cross section.
Why is NATM?
NATM is best suited for short-range (> 2 km) tunnels in regions with variable soil conditions. Its philosophy and construction method yield a more cost-effective, flexible tunneling operation when compared with the other methods.
What are the types of excavation?
Types of Excavation
- Earth excavation is removal of the layer of soil immediately under the topsoil and on top of rock.
- Muck excavation is removal of material that contains an excessive amount of water and undesirable soil.
- Unclassified excavation is removal of any combination of topsoil, earth, rock, and muck.
Why do we excavate?
excavation, in archaeology, the exposure, recording, and recovery of buried material remains. Most important excavations are the result of a prepared plan—that is to say, their purpose is to locate buried evidence about an archaeological site.