Information about tunneling

2. • PURPOSES OF TUNNELLING
• EFFECTS OF TUNNELLING ON
THE GROUND
• LINING OF TUNNELS
• ECONOMICAL ASPECTS OF
TUNNELLING
• GEOLOGICAL CONSIDERATION
FOR SUCCESSFUL TUNNELLING
• OVERBREAK
• EXAMPLES OF TUNNELS OF
INTEREST AND IMPORTANCE
INTRODUCTION

3. INTRODUCTION
Tunnels are key elements of the nation’s infrastructure. Mostly invisible
and out of sight, they play a key role in urban transportation, water and
sewerage transportation, and in hydro electric power and many other
sectors.
The seminar will cover an introduction to all forms of tunneling in a
coherent and systematic approach. Particular emphasis will be placed
on the attendees understanding both the full range of tunneling
techniques available and their applicability in various soils and physical
constraints. The seminar will also emphasize understanding and
mitigating the inevitable risks involved in tunneling.

4. PURPOSES OF TUNNELLING
from avalanches of snow or falling rock.
A Tunnel is an underground passage. In general, tunnels are at least twice as long
as they are wide and are completely enclosed on all sides, save for the openings at
each end.
A tunnel may be used by pedestrians, cyclists, motor vehicles, or rail traffic. A tunnel
may also be used for a canal or a flow of water—for consumption, for hydroelectric
purposes, or for sewers— or it may carry other utility services such
as telecommunication cables or steam pipes. Some tunnels are designed as wildlife
crossings.
Overbridges:
An overbridge can sometimes be built by covering a road, river, or railway
with brick or still arches, then leveling the surface with earth. In railway
parlance, a surface-level track that has been built or covered over is called a
covered way.
Protection for railways: A snow shed is a kind of tunnel built
to protect a railway from avalanches of snow or falling rock.

5. • Utility ducts: Utility ducts are man-made tunnels created to carry two
or more utility lines underground. Through co-location of different utilities
in one tunnel, governments and companies are able to reduce the costs
of building and maintaining utilities.
o Types Of Tunnels

6. EFFECTS OF TUNNELLING IN THE
GROUND
The "tunnel effect", when talking about long stretches of road, refers to the
environment surrounding the driver that begins to merge towards the central
point of the horizon. This effect can be noted at high speeds, when driving
on straight smooth roads. The effect is amplified if the environment
surrounding is monotonous. The "tunnelling effect" can cause nausea,
confusion to drivers as well as letting fatigue settle in at a higher rate,
making it one major cause in sleep related accidents.

8. Tunnel lining waterproofing
Various types of waterproofing materials are used in modern
tunnel construction. Solid waterproofing is made of
waterproof building organic or synthetic film filter materials,
synthetic resinous materials, and steel sheets.
Cat-in-place tunnel lining, placed in stable rock ground,
protect from water by means of external waterproof installed
before lining construction. After that reinforced framework is
performed.

9. Economical aspects of Tunneling
Tunnels have been essential feature of Railways particularly for
crossing hills and high altitude areas.. An attempt has been made
to bring out some relevant
important aspects of Tunneling.
Following factors are to be kept in mind in conception
of alignment:

10. following factors are to be kept in mind in conception of alignment:
i. Cost aspect
Execution cost
Running cost – Has bearing on decisions of grade and curve
radius
ii. Time of execution concept
Interest cost, Delayed benefit / goodwill cost
iii. Method of execution
Drill and blast method
• Prevalent method in capital rich countries, generally
require uniform stratification

11. Sedimentary rocks
Mostly, these rocks are formed under relatively uniform conditions over relatively
large areas. Subsequent metamorphism, folding and faulting, even though
relatively
complex, do not change the sedimentary rock to the extent that its original
composition and areal extent cannot be recognised.
Intrusive igneous rocks
These are less predictable than extrusive igneous rocks and the accuracy of
projection
is of the same order as their areal extent. Hence a dyke can be interpreted
between
data points and projected to depth to the approximate extent of its surface
expression.
The least reliable feature of an intrusive igneous rock mass is the contact of a
crosscutting
intrusive body.

12. Examining the cut kerf
of the Robbins
waterjet-assisted
hard-rock TBM in
granite

13. Overbreak of rock beyond the desgined periphery of a tunnel is a structural risk
which more than occasionally results in filing of a claim by the contractor. It is
difficult to estimate the overbreak risk at the time of tender with sufficient degree of
accuracy because of the uncertainty associated with the geology, construction
technique, and the interaction of these two domains.
The key variables that influence the extent of overbreak, and their interactions, are
illustrated through the proposed interaction matrix.
The assessment of overbreak for a tunnel excavated using the conventional, drill-
and-blast technique, is performed using an approach that integrates simulation
and sensitivity analysis.
OVER BREAK

15. Pir Panjal Railway
Tunnel
The Pir Panjal Railway
Tunnel or Banihal railway
tunnel is an 11.215 km (7
mile) railway tunnel
located in Pir Panjal
Range of
middle Himalayas in Jam
mu and Kashmir, India,
north of Banihal town.

17. Progress of the project :
The new 11.215 km (7 mile) long Banihal-Qazigund tunnel for the Kashmir
Railway line connecting Bichleri Valley of Banihal with Qazigund area of Kashmir
Valley has been constructed as a part of its Udhampur-Srinagar-Baramulla rail link
project. The boring was completed in four years in October 2011, its lining and laying
of rail tracks was completed in the next one year and trial run commenced on 28
December 2012. The tunnel was commissioned on 26 June 2013 and commercial
runs started from 27 June 2013.
The rail tunnel reduces the distance between Quazigund and Banihal by 17 km
(from 35 km by road to 17.5 km by train).[4]
Banihal railway station is situated at 1,702 m (5,584 ft) above mean sea level. The
railway network in Kashmir from Banihal toBaramulla is now 137 km. Until the
148 km Katra-Banihal section of Kashmir railway gets constructed in another five
years in 2018, people can travel from Jammu Tawi or Udhampur to Banihal by road
and take the train from Banihal to Srinagar through the Banihal railway tunnel.