A PRESENTATION ON TUNNELS

2.  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.

3.  There are three broad categories of
tunnels:
A. MINING Tunnels.
B. PUBLIC WORKS Tunnels.
C. TRANSPORTATION Tunnels.

4. 1. 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.

5. 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

7. 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.

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

10.  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.

12.  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.

14.  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.

15. 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.

16.  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.