This document provides an overview of tunnels, including their definition, history, construction methods, design considerations, and effects of earthquakes. Tunnels are underground passages constructed for various purposes like transportation. Key construction methods include cut-and-cover, drill-and-blast, bored tunneling using a Tunnel Boring Machine, and sequential excavation. Design requires considering factors like ground conditions, water management, tunnel usage, and seismic activity. During earthquakes, tunnels can experience ground shaking, ground failures, deformations, cracking, and other effects that must be addressed in seismic design. The Gotthard Base Tunnel case study exemplifies addressing geological challenges during tunnel construction.

1. STUDY OF TUNNELS
By-
SHAIKH ADIL
Seminar on-

2. WHAT IS TUNNEL?
 It is an underground or underwater
passageway, dug through the
surrounding soil/earth/rock
 A tunnel may be for foot or vehicular
road traffic, for rail traffic, or for a canal.
 Secret tunnels are built for military
purposes.
 Special tunnels, such as wildlife crossings,
are built to allow wildlife to cross human-
made barriers safely.

3. REASONS TO BUILD A TUNNEL
 When the lane encounters an obstacle such as
a mountain to avoid bypassing the obstacle
 Built sometimes to overcome a water obstacle
as a replacement for building a bridge above it.
 Built to connect between military posts so the
movement between them will not be visible for
the enemy
 Sometimes built for infrastructure like electricity
cables, water, communication and sewerage to
avoid damage and disruption above ground

4. HISTORY
 the first tunneling was done by prehistoric people
seeking to enlarge their caves.
 First tunnel in Babylonia was a brick-lined pedestrian
passage some 3,000 feet (900 meters) long was built
about 2180 to 2160 B.C. under the Euphrates River to
connect the royal palace with the temple
 the largest tunnel in ancient times was a 4,800-foot-
long, 25-foot-wide, 30-foot-high road tunnel (the
Pausilippo) between Naples and Pozzuoli, executed
in 36 B.C.

5.  In 1681 gunpowder was first used for blasting
the tunnels
 First time the ventilation system for tunnel was
developed in 1927 in Holland tunnel
 In 1952 James.S.Robbins comes up with a
good idea and designs the modern tunnel-
boring machine
 In 1988 Japan's 33-mile-long Seikan Tunnel, the
world's longest and deepest railway tunnel
(787 feet below sea level), connects the
islands of Honshu and Hokkaido
 In 1994 after 192 years of planning and six
years of building, the Channel Tunnel runs
under the English Channel

6. TUNNELING METHODS
 depends on
 ground conditions,
 the ground water conditions,
 the length and diameter of the tunnel drive,
 the depth of the tunnel,
 the logistics of supporting the tunnel excavation,
 the final use and
 shape of the tunnel and appropriate risk.

7. COMMONLY USED METHODS
1. CUT AND COVER
TUNNELING

8. 2. DRILL AND
BLAST
3. BORED
TUNNELING
 Done by Tunnel Boring Machine (TBM)
 It is often used for excavating long tunnels

9. 4. SEQUENTIAL EXCAVATION
METHOD Also known as the New Austrian Tunneling
Method (NATM).
 The excavation location of a proposed tunnel is
divided into segments first.
 The segments are then mined sequentially with
supports

10. PARTS OF TUNNELS

11. TUNNEL LININGS
 These are the permanent or temporary
support for keeping tunnel from collapse
and provide safe.
 Tunnel linings are grouped into three
main forms some or all of which may be
used in the construction of a tunnel:
1. Temporary ground support
2. Primary lining
3. Secondary lining

12. DESIGN
CONSIDERATIONS Water
 Constructability
 Tunnel usage
COMMON TYPES OF LINING USED IN
TUNNELS
1. Natural
support in
rock
When the
tunnel is being
bored through
good quality
rock

13. 2. 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 a tunnel

14. 3. SHOTCRETE
 Pneumatically applied mortar and concrete
are increasingly being used for the support of
underground excavations

15. 4. WIRE MESH
 Wire mesh is used to support small pieces of
loose rock or as reinforcement for shotcrete.
 Two types of wire mesh are commonly used in
underground excavations:
1. Chain-link mesh:- commonly used for fencing
2. Weld mesh:- commonly used for reinforcing
shotcrete

16. 5. IN SITU CONCRETING
 The process of placing concrete in situ
was incompatible with timber supports.
 The first uses of concrete were for tunnels
in good rock and it was only with the
introduction of steel supports that
concrete became the norm for a tunnel
lining material.
 In-situ forms used for lining tunnels are,
with few exceptions, of the travelling
type, constructed of steel.

17. 6. PRECAST CONCRETE
SEGMENTS•Most commonly used method
•Economical

18. VENTILATION IN TUNNELS
Ventilation is required because of :
 1) Dust and gas caused by drilling,
blasting, loading of excavated materials
and Shotcreting
 2) Exhaust gas and smoke discharged by
diesel
 3) Poison gas made from explosive or
organic solvent
 4) Poison gas, flammable gas or oxygen
shortage gas in ground
 5) High temperature and high humidity

19. VENTILATION DURING
CONSTRUCTION
 During construction it is necessary to ventilate
a tunnel for various reasons:
 To furnish fresh air for the workers
 To remove the dust caused by drilling,
blasting, mucking, diesel engines, and other
operations
 To remove obnoxious gases and fumes
produced by explosives

20. SEISMIC DESIGN
CONSIDERATIONS
 Underground structures constitute crucial
components of the transportation
networks
 Underground structures are constrained
by the surrounding medium
 Compared to surface structures, which
are generally unsupported above their
foundations, the underground structures
can be considered to display
significantly greater degrees of
redundancy thanks to the support from
the ground6

21. SEISMIC DESIGN VS
CONVENTIONAL DESIGN
 Seismic loads cannot be calculated accurately.
 Seismic loads are derived with a high degree of
uncertainty, unlike dead loads, live loads, or other
effects such as temperature changes.
 Any specified seismic effect has a risk associated
with it.
 Seismic motions are transient and reversing (i.e.,
cyclic). The frequency or rate of these cyclic
actions is generally very high, ranging from less than
one Hz to greater than ten Hz.
 Seismic loads are superimposed on other
permanent or frequently occurring loads.

22. GENERAL EFFECTS OF
EARTHQUAKE
1. Ground shaking
 Ground shaking refers to the vibration of the
ground produced by seismic waves propagating
through the earth’s crust
 It composed of two different types of seismic
waves
1. Body waves travel within the earth’s material. They
may be either longitudinal P waves or transverse
shear S waves and they can travel in any direction
in the ground.
2. Surface waves travel along the earth’s surface.
They may be either Rayleigh waves or Love waves.

23. GROUND FAILURE
 Ground failure broadly includes various types
of ground instability
 Such as faulting, landslides, liquefaction, and
tectonic uplift and subsidence.
 Each of these hazards maybe potentially
catastrophic to tunnel structures, although the
damages are usually localized.
 Design of a tunnel structure against ground
instability problems is often possible, although
the cost may be high.

24. TYPES OF DEFORMATIONS.
1. AXIAL AND CURVATURE
DEFORMATIONS

25. 1. OVALING (FOR CIRCULAR TUNNELS) AND
RACKING (FOR RECTANGULAR TUNNELS
SUCH AS CUT-AND-COVER TUNNELS

26. CRACK
DISTRIBUTION
ALONG THE
TUNNEL LINING
DURING
EARTHQUAKE

27. CASE STUDY
 The Gotthard Base Tunnel is a railway tunnel in the
heart of the Swiss Alps
 route length-57 km
 total of 151.84 km of tunnels
 world's longest rail tunnel.
 Detailed preliminary investigation took place in
1986.
 It came to know that there are total of 90 geologic
problem zones at site.
 most difficult zone for the tunnellers on the Piora
Basin stretch - a funnel-shaped formation filled with
sugar grained dolomite and water

28.  A thick jet of water mixed with dolomite
shot out of the mountain and flooded
the road.
 A series of 19 inclined drills were made
 finally giving the engineers the all clear.
They hit on hard rock with no water
pressure.

29. geology is very important while designing a
tunnel.
The method adopted for tunneling is based on
the type of rock and geological conditions.
tunnels are safer to the earthquake from the
other on ground structures.
necessary to consider the seismic design of
tunnel,
ventilation of tunnel is very important in tunnel
during the construction and after the
construction,
CONCLUSION

30. REFERENCES
 IS 15026 (2002): Tunneling Methods in Rock Masses -Guidelines [CED 48:
Rock Mechanics]
 HossamToma,Tunnel Lining Methods: Selection of an efficient method,
International Journal of Advanced Technology in Civil Engineering, pp 14-
20
 Bickel. (1995). Tunnel engineering handbook, 2nd edition. CBS Publishers.
 Seismic Design of Tunnels, “A Simple State-of-the-Art Design
Approach”1991 William Barclay Parsons Fellowship, Parsons Brinckerhoff,
Monograph 7
 Design features of Jammu-Udhampur-Srinagar-Baramulla Rail Link Project
(v.k.duggal dyce/con./n.rly,d.k.pandey sr den/lko/n.rly)
 Kawashima K., (2000), Seismic design of underground structures in soft
ground: a review, Geotechnical Aspects of Underground Construction in
Soft Ground, Kusakabe, Fujita & Miyazaki (eds). Balkema, Rotterdam, ISBN
90 5809 1066.
 Wang J., (1993), Seismic Design of Tunnels: A Simple State-of-the-art Design
Approach, Monograph 7, Parsons, Brinckerhoff, Quade and Douglas Inc.,
New York.
 G. Lanzano, E. Bilotta, G. Russo. “Tunnels under seismic loading: a review of
damage case histories and protection methods”.