Transcript Slide 1
Tunnel
Engineering for
Indian Railways
Pir Panjal Tunnel
Pir Panjal Tunnel
The tunnel is almost straight, extending from north to
south. It is 8.4m wide and 7.3m high.
Pirpanjal Tunnel
Pir Panjal (or T-80) is
India's longest
transportation railway
tunnel at 10.96km.
The tunnel section is a
part of the 202km
Udhampur - Srinagar Baramulla rail link
project undertaken by
the Northern Railways
Pirpanjal Tunnel
It operates 440m below
the existing Jawahar
Tunnel, which is the only
road link from the
region to the rest of
India.
Tunnel engineering at a
glance
1. Topographic survey
• Topographic survey done for
2000m length and for a width of
100m on either side of centre line
of the tunnel
• Resolution with a grid of size
25m x 25m
• Gradient of 1 in 200 adopted in
the tunnel throughout for easy
drainage
2. Geotechnical investigations
• 9 bore holes with a
maximum
depth
of
51.0m below natural
ground level
• Rotary
type
boring
machine with diamond
bits was used.
• Jointed basalt (above
crown), breccia (in the
Tunnel
section),
Amygdaloidal
basalt,
volcanic ash (below
invert)
etc
are
encountered.
3. Field tests
(a) Electrical resisitivity tests
• Current applied in the outer pair of
electrodes
• Potential difference measured at the
central pair of electrodes
• Resistivity governed by the amount of
pore water and arrange of pores
3. Field tests
(b) Pressure meter tests (Stress – Strain relationship of
soil mass and deformation modulus, E)
• Determine rock strength parameters, E for Basalt is 5000
MPa
3. Field tests
(c) Lugeon tests (Permeability
characteristics of rock mass
• Permeability values are found
to be low.
•Assessment of grouting
requirement.
3. Field tests
(d) Seismic Tomography
• Fast emerging powerful tool and precise in-situ
determination of seismic velocities
• Detailed information about the soil and rockmass
properties
• Separation of drill bore holes not more than 60m to
give better resolution
4. Tunnel Design
Design parameters:
1. Density
2. Water absorption
3. UCS
4. Core recovery
5. RQD
6. E value
7. Tensile strength
8. RMR
9. Q value
Tunnelling Video
Manual
Tunnel Boring Machine
TUNNELS IN SOUTH
CENTRAL RAILWAY
Construction of BG Single line Railway Tunnel
between Margutti (H) and Kamalapur stations
In Bidar – Gulabarga section
• Tunnel length: 1500 RM
Tunnel layout
Trolley refuge at every 100m
Main tunnel
Escape tunnel
AREA-55.19 sqm
area:25.94 sqm
Tunnel radio system VIDEO
Thank you