This document discusses various aspects of tunnel construction including definitions, purposes, factors affecting construction, major tunnels in India, shapes of tunnels, geological surveys, design considerations, construction methods, and conclusions. It defines a tunnel as an underground passageway dug through surrounding soil or rock and enclosed except at entrances and exits. Common construction methods described are cut-and-cover, tunnel boring machine (TBM), shield technique, pipe jacking, and sprayed concrete. Design considerations include alignment, tunnel lining, groundwater control, ventilation, and investigation.

1. S T J INSTITUTE OF TECHNOLOGY
RANEBENNUR
“TUNNELS CONSTRUCTIONS’’
PRESENTED BY GUIDED BY
VINAY V B HANUMESH B M
8TH SEM B. E (CIVIL) B.E., M.TECH..
ASSITANT PROFESSOR
STJIT, RANEBENNUR STJIT, RANEBENNUR

2. TUNNELS
Tunnel is an underground passageway dug through the
surrounding soil or rock and enclosed expect at the
entrance and at the exit.

3. INTRODUCTION
Made through natural
material(rock)
Empty inside
Carry the loads itself
Both ends are open to
atmosphere
Generally horizontal
Thick walled structure
looks like cylinder

4. PURPOSE OF TUNNEL
• Tunnels are used for highway traffic, railroads
and subways
• To transport water, sewage, oil and gas
• To divert rivers around dam sites while the dam
is being built
• For military and civil defense

5. FACTORS AFFECTING THE
TUNNEL CONSTRUCTION
• Ground condition
• The groundwater condition
• The length and diameter of tunnel drive
• The depth of tunnel
• The logistics of supporting the tunnel excavation
• The final uses and shape of the tunnel and appropriate
risk

6. MAJOR TUNNELS OF
THE INDIA
Tunnel name Length of tunnel Tunnel for Situated at
Pir Panjal tunnel 11.2Km long Railway Himalayas
Karbude 6.5Km long Railway Maharashtra
Natuwadi 4.3Km long Railway Mangalore to
Mumbai through
Goa
Chennai Nashri 9.2Km long Roadway Udhampur of
Jammu and
Kashmir
Bhatan 1Km long Roadway Mumbai Pune
expressway

7. SHAPES OF TUNNEL
a. CIRCULAR TUNNEL
• Constructed using either TBM or drill and blast method
in soft ground
• Greater resistance to
external pressure
• Prefer to carry water and
sewage circulation

8. b. RECTANGULAR TUNNEL
• They are constructed by cut and cover method or
immersed method or by jacked tunneling

9. c. ELLIPTICAL TUNNEL
• These tunnels serve as water sewage condition
• Difficult to construct

10. d. EGG SHAPED TNNNEL
• Narrow cross section at the bottom
• Maintain self-cleaning velocity of flow of sewage both
in dry and rainy seasons
• Resist external as well as internal
• pressure due to their circular walls

11. e. HORSE SHOE SHAPED TUNNEL
• Constructed by drill and blast method or NATM
• This form of semi-circular roof together
with arched and curved invert
• Most popular as traffic tunnels for
road and railway routes

12. GEOLOGICAL SURVEY
FOR TUNNELING
It is the systematic investigation of the
subsurface and surface of a given piece of ground
for the purpose of creating a geological map
model and feasibility studies.

13. DESIGN CONSIDERATION
OF TUNNEL
1. PARTS OF TUNNEL

14. 2. ALIGNMENT
• The road tunnel should be designed in accordance with
the respective manual for geometric design
• The alignment of tunnel must be consistent with there
alignment of the roadway leading to it
• The alignment must consider factors like the sight
distances, minimum turning radius and design speeds
in its design
• Except for maintenance reasons two way roads should
be discouraged in a single tube of tunnel for safety
reasons

15. 3.TUNNEL LINING
• These are the permanent or temporary support for
keeping tunnel from collapse and provide safe.
Tunnel lining are grouped into 3 main forms some
or all of which may be used in construction of
tunnel.
a. Temporary ground support
b. Primary lining
c. Secondary lining

16. TYPES OF TUNNEL
LINING
a. NATURAL SUPPORT TUNNEL
When the tunnels is being bored through good quality rock.

17. b. ROCK REINFORCEMENT
Steel bolts are frequently set in holes drilled
into the rock to assist in supporting the entire roof
or individual rock slabs that tend to fall into
tunnel.

18. c. SHOTCRETE
Pneumatically applied motor and concrete
are increasingly being used for the support of
underground excavation.

19. d. WIREMESH
Wire mesh is used to support small pieces
of loose rock or as reinforcement for shot Crete.

20. e. INSITU CONCRETEING
The process of placing concrete in-situ was
incompatible with timber supports. The first uses
of concrete were tunnels in good rock and it was
only with the introduction of steel supports that
concrete became the norm for tunnel lining
material.

21. 4.GROUND WATER CONTROL
Building a dry is a primary concern for tunnel
construction as a dry tunnel provides a safer, friendlier
environment costs. Based on the advanced water proofing
technologies. Today the International Tunneling
Association (ITA) recommends the following infiltration
criteria.
Allowable infiltration
• Tunnel : ≤ 0.002gal/sq. ft./day
• Underground public space : ≤0.001gal/sq. ft./day

22. 5. VENTILATION OF TUNNEL
Ventilation is required because of
 Dust and gas caused by drilling, blasting loading of excavated
material and shot crating
 Exhaust gas and smoke discharge by
diesel
 Poison gas flammable gas or oxygen
shortage gas in ground
 Poison gas made from explosive
or organic solvent
 High temperature and high humidity

23. 6. INVESTIGATION
i. Mapping (Topographic, geologic, etc...)
ii. Geophysical surveying (especially seismic
velocity of rocks)
iii. Trial pits & boreholes
iv. General and local stability analysis
v. Decide to excavation method

24. CONSTRUCTION
METHODS OF TUNNELING

25. 1.CUT AND COVER
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.
 A shallow place (10-12 m)
 Practical & easier in construction
 May cause traffic problems, noise & dust
 Not Economical if >12 m/dewatering

26.  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

27. Cut and cover
Bottom up
method
Structurally
independent of
the support walls
Top down
method
Side support
walls, main
contributor in the
tunnel structural
system

28. 2. TUNNEL BOREING MACHINE
 Excavation is done by Tunnel
Boring Machines (TBM's).
 Involves digging a tube-like
passage through the earth.
 Long tunnels construction.
 Competent rocks that provide
adequate geological stability
for boring a long section tunnel
without structural support.
 Used for tunneling under
bodies of water.
 Capital intensive with high
mobilization costs

29. • Tunnel boring machine facts
 Weight : 800 tones, Length : 430 ft.
• Average Production Rate: 5-10 m/day
• Diameter:
1 – 14.4 m(Hard Rock TBM)
1 – 19.25 m (Soft Ground TBM)
TBM
Mechanical
support TBM
Compressed air
TBM
Slurry shield
TBM
Earth pressure
balance
machine

30. 3. SHIELD TECHNIQE
.
 This method involves the use of
shield machine to drive the
tunnels below the ground
 After completion of a work
shaft, the shield machine is
lowered into the shaft and
assembled there before
excavation and construction of
the tunnels using precast
concrete lining segments of
about 1.2 meter width
 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

31. 4. PIPE JACKING
In pipe jacking, hydraulic jacks are used to push specially
made pipes through the ground behind a TBM or shield. This
method is commonly used to create tunnels under existing structures
such as roads or railway. Tunnels constructed by pipe jacking are
normally small diameter bores with a maximum size of around
3.22m(10ft).

32. 5. SPRAYED CONCRETE
• New Austrian Tunneling Method ( NATM)
• Utilizing the self supporting capability of the ground hence
achieving an economically sound ground system
• Used with dry soil where roads are used for excavation
• Support element is shot crating, providing interlocking &
continuous support to the ground
• SEM is slower than TBM constructing long tunnels

33. 6. IMMERSED TUNNEL
• More feasible & efficient technique for a tunnel crossing a
waterway
• It provides ,
o Good weather
o Reasonable water currents
o Sufficient bearing capacity for riverbed/seabed

34. Construction sequence
o Dredging the trench in river or sea bottom
o Pre-fabrication of tunnel sections and sealing ends with
bulkheads
o Floating the sections to the tunnel trench
o Lowering the section to seabed
o Joining the sections together underwater
o Removing the temporary bulkheads
o Backfilling the trench

35. CONCLUSION
• The most governing factor of choice is the soil
conditions
• The safety, level of risk, constructability, speed and
cost
• It is an idea for which every civil engineer must be
proud of
• Implementation of this concept can reduce the amount
of fossil fuel import
• It can save the country’s environment from
deterioration

36. REFERENCES
• Predicting tunnel squeezing problems in weak heterogeneous
rock masses” Tunnels and Tunneling International Part 1 –
November 2000, Part 2 – December 2000. Evert Hoek and Paul
Marinos
• “construction methods of tunnel”,
https://en.wikipedia.org/wiki/Tunnel_construction
• “design consideration”,
https://en.wikipedia.org/wiki/Tunnel_construction
• “Status of tunneling and underground construction activities
and technologies in India”. R.K.Goel, Central Mining Research
Institute Regional Centre, CBRI, Roorkee 247 667, India. Received
15 March 2001; received in revised form 3 May 2001; accepted 4
May 2001

37. THANK YOU