Tunnel

TUNNELS

Presented By:

PRABISH BISHUNGKHESHYAM NARAYAN

MANISH MEENAHAKIM SINGH

What is a TUNNEL?

A Tunnel is a tube hollowed through soil or stone.

Constructing a tunnel is one of the most complex challenges in the field of civil engineering.

There are many different ways to excavate a tunnel, including manual labour, explosives, rapid heating and cooling, tunnelling machinery or a combination of these methods.

What are the Types?

There are three broad categories of tunnels:

A. MINING Tunnels.B. PUBLIC WORKS Tunnels.C. TRANSPORTATION Tunnels.

MINING Tunnels1. Mine tunnels are used

during ore extraction, enabling labourers or equipment to access mineral and metal deposits deep inside the earth.

2. They cost less to build. 3. Mine tunnels are not as safe

as tunnels designed for permanent occupation.

PUBLIC WORKS Tunnels

1. Public works tunnels carry water, sewage or gas lines across great distances.

2. The earliest tunnels were used to transport water to, and sewage away from, heavily populated regions.

3. Engineers used an extensive network of tunnels to help carry water from mountain springs to cities and villages

Public Works Tunnel

TRANSPORTATION Tunnels

1. Before there were trains and cars, there were transportation tunnels such as canals.

2. Canals are artificial waterways used for travel, shipping or irrigation purpose.

3. Trains and cars had replaced canals as the primary form of transportation, leading to the construction of bigger, longer tunnels. 

Transportation Tunnel

TUNNELLING METHODS

Shield Tunnelling Method CUT and COVER Tunnelling Method Classical Method Drill and Blast Tunnel Boring Machines Tunnel Jacking

Shield Tunnelling Method

This method involves the use of shield machine to drive the tunnels below the ground.

This construction method causes minimal disruption to traffic and the environment because all the work takes place below ground and the ground level environment is unaffected.

Shield Tunnelling machine

CUT and COVER Tunnelling Method This construction method, whereby the site is fully

excavated, the structure built and then covered over, uses diaphragm walls as temporary retaining walls within the site area.

Step one : Construction of diaphragm walls, pin piles, and decking.

Step two : Excavation within the diaphragm walls, installing struts as work progresses.

Step three : Construction of permanent floor slabs and walls.

Step four : Fitting out the internal structures, backfilling, and reinstating the surface structures.

CUT and COVER

Tunnelling

Method

Tunnel engineers, like bridge engineers, must be concerned with an area of physics known as statics.

Statics describes how the following forces interact to produce equilibrium on structures such as tunnels.

Tension, which expands, or pulls on, material.Compression, which shortens, or squeezes

material.Shearing, which causes parts of a material

to slide past one another in opposite directions.

Torsion, which twists a material.

The tunnel must oppose these forces with strong materials, such as masonry, steel, iron and concrete.

In order to remain static, tunnels must be able to withstand the loads placed on them. 

Dead load refers to the weight of the structure itself .

Live load refers to the weight of the vehicles and people that move through the tunnel.

ADVANTAGES OF Tunnels

Reduction of harmful effects during construction.

Preservation of the forested land. Avoidance of harmful effects in residential

areas (Noise pollution). Limitation of harmful effects on historic

monuments. Reduction of greenhouse gas emissions. Traffic congestion control.

THANK YOU