What is the cut and cover tunneling method?
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 are the methods of tunnel construction?
Methods of Tunnel Construction
- Cut and cover method.
- Bored tunnel method.
- Clay kicking method.
- Shaft method.
- Pipe jacking method.
- Box jacking method.
- Underwater tunnels.
What are the three common tunneling techniques?
There are three basic types of tunnel construction in common use:
- Cut-and-cover tunnel, constructed in a shallow trench and then covered over.
- Bored tunnel, constructed in situ, without removing the ground above.
- Immersed tube tunnel, sunk into a body of water and laid on or buried just under its bed.
What is hydraulic design of tunnel?
Hydraulic tunnels are usually lined with steel, cast in situ concrete or sprayed concrete. The use of geomembranes allows the combination of continuous watertightness and improved friction properties with the strength of the concrete lining at a much lower cost.
What is cut and cover structure?
In a cut and cover tunnel, the structure is built inside an excavation and covered over with backfill material when construction of the structure is complete. Cut and cover construction is used when the tunnel profile is shallow and the excavation from the surface is possible, economical, and acceptable.
What is a cut and cover?
Cut and cover construction involves using excavation equipment to dig a large trench or rectangular hole in the ground which is then covered by a concrete deck. Once the deck is in place, surface activity can largely resume as construction works continue below.
What is tunnel design?
Tunnel design is an interdisciplinary subject, involving geotechnical engineering, geology, geochemistry, and hydrogeology. In this chapter, the main concepts of tunnel design will be presented.
What is tunnel and its types?
There are three basic types of tunnel construction in common use: Cut-and-cover tunnel, constructed in a shallow trench and then covered over; Bored tunnel, constructed in situ, without removing the ground above. There are also Conveyance Tunnels and Traffic Tunnels.
What are the components of tunnel?
In order to understand how a Tunnel Boring Machine works, we will divide its components into three parts: Cutting Head (front) Tunnel Field (middle) Trailing Gear (rear)…Soft Ground TBMs
- Slurry Shield.
- Earth Pressure Balance.
- Open Face Type.
What is the purpose of diversion tunnel?
The tunnel is excavated in either of the abutments to divert the entire river flow, both its usual and flood discharges, around the dam site. The cofferdams are watertight structures, usually earthen embankments, constructed upstream and downstream of the site to isolate the construction area that is to be kept dry.
What is diversion tunnel in a dam?
When a dam is to be built, a diversion tunnel is usually bored through solid rock next to the dam site to byPAss the dam construction site. The dam is built while the river flows through the diversion tunnel.
What is cut-and-cover tunneling?
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.
Is tunneling a disruptive construction technique?
As such, it is a disruptive technique, but it is also usually the most economical construction method. Where the tunnel alignment is beneath a city street, the construction may cause interference with traffic, utilities, businesses and other urban activities.
How are tunnels built to deal with contaminated groundwater?
For the tunnels of the East Side Access Project in Queens, New York, the presence of contaminated ground water necessitated the use of rigid support of excavation using a combination of diaphragm (slurry) walls and jet grouting to limit the groundwater drawdown to less than 2ft (600mm).
What is an example of cut-and-cover construction?
A recent example of extreme cut-and-cover construction is the Asia transition structure of the Eurasia Tunnel in Istanbul, Turkey, in which the excavation was 168m long by 35m deep and with variable width, all constructed within a few meters of the Bosphorus Strait.