TUNNELS

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TUNNELS
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TERMINOLOGY for UNDERGROUND STRUCTURES

• Adit.....................................galeri
• Tunnel................................tünel
• Subway..............................metro
• Shaft...................................baca
• Chamber............................oda
• Portal.................................ana giris
  veya çikis
• Pilot adit.............................yan
  galeri, pilot galerisi
• Centre................................merkez,
  eksen
• Face...................................ayna
• Wall site..........................yan, kenar,
  duvar
• Floor...................................taban
• Roof...................................tavan

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• Overbreak.............................asiri
  sökülme
• Excavated profile..................kazi profili
• Natural archling....................dogal
  kemerlenme
• Load......................................yük
• Support.................................destek,
  iksa
• Failure...................................yenilme,
  çökme
• Gentle failure........................yavas
  yenilme
• Rock burst............................kaya
  patlamasi
• Squeezing ground................sikisan zemin
• Swelling ground....................sisen zemin
• Clay-filled joint.......................kil
  dolgulu eklem
• Long term stability.................uzun süreli
  duraylilik
• Ground treatment..................zemin
  iyilestirmesi
• Support before excavation....kazi öncesi
  destekleme

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• Jet grouted roof cover..............jet grouting
  ile iyilestirilmis tavan örtüsü
• Shotcrete initial lining..............püskürtme
  beton baslangiç çizgisi
• Jet grouted floor cover............jet grouting
  ile iyilestirilmis döseme
• Top heading............................kalot
  (Crown)
• Invert.......................................stros
  (Bottom excavation)
• Bench......................................üzengi
  çizgisi
• Final concrete lining................sonuncu
  beton kaplama (nihai beton kaplama çizgisi)
• SHIELD tunnelling method..............KALKAN
  Yöntemi
• CUT COVER tunnelling method....AÇ-KAPA Yöntemi
• TBM (Full face Total Boring Machine).....TÜM
  KESIT KAZI MAKINASI

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TERMINOLOGY for EXCAVATIONS of ROCKS SOILS

• DRILLING....................Sondalama
• Hardness.........................Sertlik
• Toughness.......................Dayanim direnç
• Abrasiveness...................Asindiricilik
• Structure..........................Jeolojik yapi
• Drilkling fluids..................Sondaj sivisi
• AUGERING..................Burgulama
• MACHINE BORING.....Mekanize tünel açma
• Total Boring Machine (TBM)
• Full face excavation
• BLASTING...................Patlatma

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• SCRAPING...................Kazima (makinayla)
• RIPPING.......................Kirarak kazima
• DIGGING......................Kazma
• GROUND WATER........yeraltisuyu
• Control of groundwater
• Groundwater flow
• Rate of flow
• Volume of flow
• Boundaries

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TUNNEL DESCRIPTION

• Made into natural material (rocks)
• Empty inside
• Carry the loads itself
• Both ends are open to atmosphere
• Generally horizontal
• Thick walled structure looks like cylinder

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1- Kilit (anahtar) tasi........................Key
stone 2- Kemer...................................
........Arch 3- Ayak (duvar)......................
..........Wall 4- Taban...........................
................Floor 5- Üzengi...................
.......................Bench 6- Üzengi çizgisi
(düzeyi)...............Bench line or plane 7-
Kalot............................................T
op heading 8- Stros...............................
.............Invert 9- Ano........................
......................Ano (unit)
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Tunnel Section for Swelling Ground
1- Digging section 2- Support 3- Swelling
section 4- Pressurized area 5- Flow direction of
water
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SURFACE EXCAVATIONS

• Deformation failure

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UNDERGROUND EXCAVATIONS

• In Rock
• In Sediment
• Stability Arching
• Water
• Dry tunnel...............above water table
• Wet tunnel..............below water table
• Gases
• Carbon dioxide (CO2)
• Carbon monoxide (CO)
• Methane (CH4)
• Hydrogen sulphide (H2S)
• Other gases

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• Gas bursts......................gaz patlamasi
• Rock falls........................kaya düsmesi
• Rock bursts....................kaya firlamasi
• Squeezing ground..........sisen kabaran zemin
• Temperature
• Subsidence

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EXPLORATION INVESTIGATIONS RELATED of SLOPE
STABILITY

• Geomorphologic maping and preparation of
  longitudinal cross sections
• Geological maping surveyings (aerial
  photographs)
• Geophysical surveyings
• Underground explorations, boreholes
• Ground water surveyings
• Laboratory tests
• Model studies

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SURFACE EXCAVATIONS

• Permanent
• Short term excavations

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SUBSURFACE EXCAVATIONS

1. GEOLOGY
2. Soil profile or hard rock geology
3. Structure
4. Ground water (hydrogeology)
5. Stability

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• INVESTIGATIONS
• Mapping (Topographic, geologic, etc...)
• Geophysical surveying (especially seismic
  velocity of rocks)
• Trial pits boreholes
• General and local stability analysis
• Decide to excavation method

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UNDERGROUND EXCAVATIONS

• Adit, shaft, incline, large chamber
• Tunnel
• Subway metro
• Underpass
• Shelter
• Power house
• Ware house, store, mining ...etc

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GASES (can be lethal or burst)

• Carbon monoxide (CO) 0.97 of air
• Carbon dioxide (CO2) 1.53 of air
• Methane (CH4) 0.55 of air
• (Highly explosive with air) marsh gas
• Hydrogene sulphide (H2S) 1.19 of air
• (Highly toxic and explosive)
• Sulphur dioxide (SO2)

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• ROCK FALL
• SQUEEZING GROUND (sand, silt, shale, clay)
• ROCK BURST
• BULKING (Increase in volume, 10-40)

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FACTORS EFFECTING EXCAVATION of ROCKS

• Mineralogical composition of rocks
• Texture fabric
• Petrographic features
• Structure
• Rock mass
• Strike dip of beds in relation to face of
  excavation
• Intensity of tectonic disturbances
• Degreee of weathering

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RESISTANCE of ROCKS to EXCAVATION

• Loose soils
• Soil easy to spade (bel ile kazmak)
• Soil easy to dig
• Crumbling weak rocks (ufalamak)
• Rocks easy to blast
• Rocks difficult to blast
• Rocks very difficult to blast

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TUNNELLING METHODS
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SHIELD TUNNELLING METHOD

• 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.

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CUT and COVER TUNNELLING METHOD

• 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.
• 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.

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TBM (Tunnel Boring Machine)

1. Mechanical-support TBM
2. Compressed-air TBM
3. Slurry shield TBM
4. Earth pressure balance machine
5. Mixed-face shield TBM

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1- Mechanical Support TBM

• A mechanical-support TBM has a full-face
  cutterhead which provides face support by
  constantly pushing the excavated material ahead
  of the cutterhead against the surrounding ground.

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2- Compressed-Air TBM

• A compressed-air TBM can have either a full-face
  cutterhead or excavating arms. Confinement is
  achieved by pressurizing the air in the cutter
  chamber.

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3- Slurry Shield TBM

• A slurry shield TBM has a full-face cutterhead.
  Confinement is achieved by pressurizing boring
  fluid inside the cutterhead chamber.

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4- Earth Pressure Balance Machine

• An earth pressure balance machine has a full-face
  cutterhead. Confinement is achieved by
  pressurizing the excavated material in the
  cutterhead chamber.

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5- Mix-Face Shield TBM

• Mix-face shield TBMs have full-face cutterheads
  and can work inclosed or open mode and with
  different confinement techniques.

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EFFECT of GEOLOGICAL STRUCTURES to TUNNEL
EXCAVATION

• Effect of soil layers horizontal, vertical and
  inclined layers have different kinds of loading
  conditions for tunnels.

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• Effect of faults the relation between the fault
  slope direction and the tunnel direction, width
  of the fault zone, type and thickness of the fill
  material and the hydrostatic pressures in both
  sides of the fault are some problems in the
  tunnelling.

Relation between the fault zone and the tunnel
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• Tunnel excavations in the slopes the
  discontinuities (layers, fissures) inclined
  inside or outside of the slope are very important
  regarding the stress and strength of the tunnel.

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• Effect of the folds While tunnel is excavated in
  an area that contains folded rocks, different
  stresses and conditions may occur depending on
  the fold type.

Fold axis and the tunnel direction is parallel
Fold axis and the tunnel direction is vertical
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CLASSIFICATION of ROCKS for TUNNELING PURPOSES
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• Classification of rocks for engineering purposes
  is needed in analyzing the project costs and to
  obtain an economic and reliable solution.
• The classification of the rocks, that the tunnel
  will be constructed in, is first done by
  Terzaghi. But, it is too general and gives
  qualitative results.

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TUNNEL ROCK CLASSIFICATION by TERZAGHI
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Laufer classified tunnel rocks to 7 groups
according to stand-up time
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Rock classification and determination of
unsupported span
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URFA IRRIGATION TUNNEL
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ONE of the LONGEST IRRIGATION TUNNELS in the WORLD
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• Consist of two concrete lined tunnels each of
  which is 7.62 m in diameter and 26.4 km in length
  discharging water from the reservoir of Atatürk
  Dam.