Tunnel Engineering for Indian Railways

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Tunnel Engineering for Indian Railways
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Pir Panjal Tunnel
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Pir Panjal Tunnel
The tunnel is almost straight, extending from
north to south. It is 8.4m wide and 7.3m high.
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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

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Pirpanjal Tunnel

• It operates 440m below the existing Jawahar
  Tunnel, which is the only road link from the
  region to the rest of India.

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Tunnel engineering at a glance
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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
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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.
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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

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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

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3. Field tests

• (c) Lugeon tests (Permeability characteristics of
  rock mass
• Permeability values are found to be low.
• Assessment of grouting requirement.

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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

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4. Tunnel Design

• Design parameters
• Density
• Water absorption
• UCS
• Core recovery
• RQD
• E value
• Tensile strength
• RMR
• Q value

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Tunnelling Video

• Manual
• Tunnel Boring Machine

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TUNNELS IN SOUTH CENTRAL RAILWAY
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Construction of BG Single line Railway Tunnel
between Margutti (H) and Kamalapur stations In
Bidar Gulabarga section
Tunnel length 1500 RM
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Tunnel layout
Trolley refuge at every 100m
Main tunnel
Escape tunnel
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AREA-55.19 sqm
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area25.94 sqm
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Tunnel radio system VIDEO
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Thank you