1. Grouting using PUR in extreme geological and weather conditions in Iceland
By Tomasz Najder, Ph.D Civ. Eng.
Senior Consultant, Najder engineering, SE Saltsjöbaden Sweden 1
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2. Location of the projects
Breiđalsheiđi and Botnsheiđi Project
Héðinsfjarðargöng Project
Kárahnjúkar Hydropower Project
Location of the projects 2
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3. 3 Icelandic geology 3 2 cm/year 2 cm/year Nord-America Plate
Eurasia Plate
Eurasia Plate
Icelandic geology 3
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4. Case study – Ísafjörður Project (road tunnels): grouting for rock sealing and stability. Conditions: very high water ingress from the fault under high water pressure into D&B tunnels Water pressure ~ approx. 60 bars Water inflow ~ 50 l/s/hole Water temperature ~ +20 ºC
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5. Limited rock permeability for cement based grouts
Ísafjörður
Location of Ísafjörður
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6. fault 2
Leakage l/s !!!
No probe holes !!!
fault 1
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7. X = wash-out Rock grouting in Breiđalsheiđi and Botnsheiđi (Iceland)
Water pressure ~ approx. 60 bars
Water inflow ~ 50 l/s/hole
Water temperature ~ +20 ºC
fault
water
Water velocity ~ 3m/s
= wash-out X
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Cement grouting ????

8. mineral component (OMC) (sequential grouting)
1-component PUR
Hydrophilic PUR
– limited range
of penetration!
components A+B
Component B
- polyisocyonate
2-component PUR
Component A
- polyol
components A+B
components A+B
Proposal:
2-component PUR or
mineral component (OMC)
(sequential grouting)
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9. Final result of grouting
Drilling and grouting pattern for Fault 2
Drilling and grouting pattern for futher “normal” chainage
Fault 2
Inserting of mechanical packers
in high water pressure conditions
Final result of grouting
Drilling for grouting
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10. Case study - Kárahnjúkar Headrace Tunnels: grouting for rock sealing and stability. Conditions: very high water ingress under water pressure of 20 bars into D&B and TBM tunnels. Cold water (+1 °C °C ). Very wide faults filled with clay and boulders
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11. Kárahnjúkar Hydropower Project 2006-2008
Diversion Tunnels at dam 2.4 km (Kar 14)
Headrace Tunnel 53.0 km (Kar 14)
Grouting galleries at dam  0.5 km    (Kar 14)
Cable tunnel  km
Hraun Diversion 2.0 km
Grjótá Diversion km
Adit km (Kar 14)
Adit km (Kar 14)
Adit km (Kar 14)
Surge Tunnel km (Kar 14)
Drainage Tunnel 0.7 km (Kar 14)
Penstocks km (2x)
Access to Powerhouse 1.0 km
Tailrace Tunnel km
Total Tunnel Length: 73.0 km (D&B=10 km, TBM=63 km)
Kárahnjúkar Hydropower Project 11
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12. TBM
D&B
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13. Low temperature problems with cement based grouts
Climate
Low temperature problems with cement based grouts
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14. 14 14 Gravel and clay filled fault at the cutterhead
Stage 2: huge water ingress from the fault;
TBM cutterhead passed the fault
Stage 3: wash-out of the fill from the fault (TBM)
Stage 4: material washed out from the fault
Stage 1: TBM in progress in water scenery 14
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15. Wide fault (coobles “cemented” with clay)
Question of time....
Water:+1 °C ÷ +65 °C
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16. 16 Bimbar inflatable reusable packers after one inserting operation
Double set of BVS inflatable, disposable, none drillable packers
How to insert the packer ????
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17. One-component PU resins
Fast reacting two-component PU resins
Fast setting two-component urea-silicate resins (foams)
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18. Fault above tunnel invert (D&B) after wash-out of fill material
ca. 8m
Fault above tunnel invert (D&B) after wash-out of fill material
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19. Solution chosen → urea – silicate foam
SPECIFIC CARACTERISTIC
IN PRACTICAL APPLICATION  
WILKIT FOAM T
GEOFOAM
PUMPING SYSTEM
SIMILAR
INJECTION RATIO
1/1
EXPANSION RATIO (V)
FILLING DRY HOLES
AT 10º C
AT 25º C
V 20
V 40
V 15
V 30
RATIO OF PERFORMANCE IN VERY HIGH WATER FLOW
AS SEEN IN KARAHNJUKAR %
> %
COUNSELLED TO INJECT AGAINST HIGH WATERFLOWS +
+++
TOUGHNESS OF FOAM
FIRE PROTECTION
EURO CLASS B2
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20. Case study - Héðinsfjarðargöng Project (road tunnels): grouting for rock sealing and stability. Conditions: very high water ingress under water pressure of 40 bars into D&B tunnels. Cold water (+2 °C). Very wide faults filled with clay and boulders. Sections with unstable tunnel’s faces and crowns
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21. Water inflow into Icelandic rock mass:
- Ólafsfjördur Tunnel
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22. Ólafsfjörður Tunnel. Water in front of the face: water ingress in the hole ~ 50 l/s
Ólafsfjörður Tunnel. Water in front of the face: water ingress ~ 5-30 l/s/hole
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23. Water ingress in heavy leaking zones
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24. Héðinsfjarðargöng Project - leakage at the face of Ólafsfjördur Tunnel
Héðinsfjarðargöng Project – face collapse at Ólafsfjördur Tunnel  
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25. Fault above tunnel invert before wash-out of fill material
Fault above tunnel invert after wash-out of fill material
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26. Fault above tunnel invert after PUR pre grouting
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27. Large fault grouted with PUR (Ólafsfjörður Tunnel)
Stone from the face grouted with PUR
- solid form like amber of PU resin
(Ólafsfjörður Tunnel)
Large fault grouted with PUR (Ólafsfjörður Tunnel)
Stone from the face grouted with PUR
- solid form like amber of PU resin
(Ólafsfjörður Tunnel)
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PUR as “hard” amber (Ólafsfjörður Tunnel)

28. λ WilkitFoam, GeoFoam λ = 15÷30 x CarboPur λ = 3÷5 x Factor λ 28
wash-out effect
ground water velocity
15 mm/sec
De Neef Scandinavia AB 1991
Factor λ
= relation between volume of material grouted / material still remaining in the rock mass after hardening vs. ground water velocity in mm/s
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29. Water is enemy to cement based grouts
(dilution)
water
cement particles
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30. PU resins love water for reaction
polyurethanes
water
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31. PUR and OMR OPC or PUR ??? Hydraulic conductivity < Lu ≈ 10-15
Winter conditions (temp ºC)
High water velocity
Big caverns
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32. Thank You for Your attention!
THE END
Thank You for Your attention!
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