1. (Part 30, PP 2007, animation+p/r : 2015.06.02 short version compr.)
Part 30/2 TrV Beprövade tekniska lösningar för ”vattendrabbade” tunnlar i komplicerade hydrogeologiska bergförhållande
VI-2015 revised 2016
(Part 30, PP 2007, animation+p/r : short version compr.)
Copyright notice Unauthorised copying of this presentation as whole or in parts in any form or by any means, electronic, photocopying, recording or otherwise, without prior written permision is prohibited.
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2. The Great Melen Project in Istanbul
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The Great Melen Project in Istanbul
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3. The Great Melen Project in Istanbul
There are two ways to set, or harden, liquid sodium silicates for grouting applications.
The first way is by lowering the silicate’s pH. This causes the SiO2 species to polymerize into a gel. Some setting agents will hydrolyze over time and form an a
cid that will set the silicate. By controlling the composition of the setting agent, and therefore the rate of hydrolysis, the gel time of the grout can be tightly controlled. The second way to set a silicate grout is to react it with soluble metals to form insoluble metal silicates.
These grouts generally have higher strength and are lower in cost. Typically, PQ’s N® sodium silicate is used for grouting applications. It is diluted to reduce its viscosity, so that it penetrates soils more easily.
The viscosity adjustment takes into account the soil permeability and the strength requirement of the grouted mass.
The strength of a silicate-grouted soil is influenced by several factors: concentration of silicate in the grout formulation composition and particle size distribution
of the soil selection and amount of hardening agents  chemistry of the surrounding waters Soil grouting and ground modification with sodium silicate is a sophisticated engineering application and requires specialized equipment and expertise.
The Great Melen Project in Istanbul
Probe drillings related to the geological profile
Exploration inadequate even with 2 probe holes
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4. Bosphorus
There are two ways to set, or harden, liquid sodium silicates for grouting applications.
The first way is by lowering the silicate’s pH. This causes the SiO2 species to polymerize into a gel. Some setting agents will hydrolyze over time and form an a
cid that will set the silicate. By controlling the composition of the setting agent, and therefore the rate of hydrolysis, the gel time of the grout can be tightly controlled. The second way to set a silicate grout is to react it with soluble metals to form insoluble metal silicates.
These grouts generally have higher strength and are lower in cost. Typically, PQ’s N® sodium silicate is used for grouting applications. It is diluted to reduce its viscosity, so that it penetrates soils more easily.
The viscosity adjustment takes into account the soil permeability and the strength requirement of the grouted mass.
The strength of a silicate-grouted soil is influenced by several factors: concentration of silicate in the grout formulation composition and particle size distribution
of the soil selection and amount of hardening agents  chemistry of the surrounding waters Soil grouting and ground modification with sodium silicate is a sophisticated engineering application and requires specialized equipment and expertise.
second probe hole (not performed)
fault 6m
second probe hole (not performed)
tunnel
40m
dip
1 probe hole only
the end of excavation (planned)
The Great Melen Project in Istanbul – optional case → cross section
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5. ?? Necessity of probe (exploratory) holes! Tunnelling contractors
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Héðinsfjarðargöng Project – face collapse at Ólafsfjördur Tunnel (high water pressure in the fault located to close to the blasting front !!!) 
Ólafsfjördur Tunnel – weak zone not detected
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6. Drilling for pre grouting (umbrella) – Arrowhead Tunnels (USA)
There are two ways to set, or harden, liquid sodium silicates for grouting applications.
The first way is by lowering the silicate’s pH. This causes the SiO2 species to polymerize into a gel. Some setting agents will hydrolyze over time and form an a
cid that will set the silicate. By controlling the composition of the setting agent, and therefore the rate of hydrolysis, the gel time of the grout can be tightly controlled. The second way to set a silicate grout is to react it with soluble metals to form insoluble metal silicates.
These grouts generally have higher strength and are lower in cost. Typically, PQ’s N® sodium silicate is used for grouting applications. It is diluted to reduce its viscosity, so that it penetrates soils more easily.
The viscosity adjustment takes into account the soil permeability and the strength requirement of the grouted mass.
The strength of a silicate-grouted soil is influenced by several factors: concentration of silicate in the grout formulation composition and particle size distribution
of the soil selection and amount of hardening agents  chemistry of the surrounding waters Soil grouting and ground modification with sodium silicate is a sophisticated engineering application and requires specialized equipment and expertise.
Drilling for pre grouting (umbrella) from back position and through cutter head
The principles for execution of the probe drilling and pre grouting with holes through A-ports in the cutter head (for almost horizontally holes) – green holes and through the B-ports from the “back position” inclined 7.5º outwards – blue holes
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Drilling for pre grouting (umbrella) – Arrowhead Tunnels (USA)
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Drilling for pre grouting (umbrella) from back position – Arrowhead Tunnels (USA)

7. There are two ways to set, or harden, liquid sodium silicates for grouting applications.
The first way is by lowering the silicate’s pH. This causes the SiO2 species to polymerize into a gel. Some setting agents will hydrolyze over time and form an a
cid that will set the silicate. By controlling the composition of the setting agent, and therefore the rate of hydrolysis, the gel time of the grout can be tightly controlled. The second way to set a silicate grout is to react it with soluble metals to form insoluble metal silicates.
These grouts generally have higher strength and are lower in cost. Typically, PQ’s N® sodium silicate is used for grouting applications. It is diluted to reduce its viscosity, so that it penetrates soils more easily.
The viscosity adjustment takes into account the soil permeability and the strength requirement of the grouted mass.
The strength of a silicate-grouted soil is influenced by several factors: concentration of silicate in the grout formulation composition and particle size distribution
of the soil selection and amount of hardening agents  chemistry of the surrounding waters Soil grouting and ground modification with sodium silicate is a sophisticated engineering application and requires specialized equipment and expertise.
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The Great Melen Project in Istanbul – drilling from B-ports (back position)
The Great Melen Project in Istanbul – drilling from A-ports (through cutterhead)
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Drilling from A-ports (through cutterhead) with preventers (close mode) and without preventers (open mode)
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10. The Great Melen Project in Istanbul
Water ingress before annulus grouting
The Great Melen Project in Istanbul
7.439%
Mucking impossible
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11. Water ingress still after annulus grouting: – necessity of cut-off membranes with PUR or OMR
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12. The Great Melen Project. Cut-off grouting (proof grouting) with PUR/OMR
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13. The Great Melen Project in Istanbul – grouting options
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The Great Melen Project in Istanbul – grouting options
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14. One of the largest problems for sub-water
Safety:
One of the largest problems for sub-water
tunnelling is uncontrolled water ingress.
Two of the biggest risks are:
1. Immediate flooding.
2. Ground collapse associated with
water ingress.
Safety:
One of the largest problems for sub-water
tunnelling is uncontrolled water ingress.
Two of the biggest risks are:
1. Immediate flooding.
2. Ground collapse associated with
water ingress.
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15. 2. Dränering vs isolering vs injektering för tunnels täthet
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16. Principles of tunnel sealing (valid for D&B method)
or shotcrete
or shotcrete
1. Grouting of rock mass: pre- and optionally post grouting.
2. Drainage and waterproof membranes.
3a. Primary shotcrete layer and waterproof (?) secondary shotcrete layer performed with anti-cracking
netting (mesh) and/or fiber + waterproofing additives.
3b. Primary shotcrete layer and waterproof secondary layer performed as in situ cast-in-place
concrete lining without reinforcement or reinforced – optionally with anti-cracking netting (mesh)
and/or fiber + waterproofing additives.
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18. Typical shotcrete final lining detail
Presented drawing displays a typical shotcrete final lining section with waterproofing system, welded wire fabric (WWF), lattice girder, grouting hoses for contact grouting and a final shotcrete layer with PP fiber addition
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19. Example for drainage into the side pipe
The groundwater flowing into the tunnel invert is collected with a granular filter and a perforated pipe in the longitudinal direction, placed in the deepest part in the invert
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Example for drainage into the side pipe

20. Héðinsfjarðargöng Project – tunnel excavation
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Héðinsfjarðargöng Project – tunnel excavation

21. Water ingress in heavy leaking zones
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Water ingress in heavy leaking zones

22. Fault above tunnel invert after PUR pre grouting
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Fault above tunnel invert after PUR pre grouting

23. Stone from the face grouted with PUR
– solid form like amber of PU resin
(Ólafsfjörður Tunnel)
Large fault grouted with PUR (Ólafsfjörður Tunnel)
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24. PUR as “hard” amber (Ólafsfjörður Tunnel)
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PUR as “hard” amber (Ólafsfjörður Tunnel)

25. Fault above tunnel invert before wash-out of fill material
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Fault above tunnel invert before wash-out of fill material
Fault above tunnel invert after wash-out of fill material

26. Tunnel finishing works:
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Tunnel finishing works:
grouting + drainage + waterproofing membrane (+ thermal isolation) + shotcrete
Tunnel primary works

27. Thank You for Your attention!
THE END of Part 2
Thank You for Your attention!
Ph.D Civ. Eng. Tomasz Najder
Senior Consultant
Najder Engineering AB
Movägen 3,
Saltsjöbaden - Sweden
Org. no: – 5433
Tel: 0046 (0)
Fax: 0046 (0)
Mobil: 0046 (0)
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