Post on 11-May-2017
B. LeistH. EversW. LeechJ. KroyerJune 12, 2007
B. LeistH. EversW. LeechJ. KroyerJune 12, 2007
Kárahnjúkar HEP
Extreme Underground ConstructionKárahnjúkar HEP
Extreme Underground Construction
Snæ-fell
Eyja-bakkar
12.2003
Jökulsá á DalFjarðaál
Egilsstaðir
Reyðarfjörður
FL 3&42x220 kV
Laga
rfljót
Þrándar-jökull
Mývatn
Jöku
lsáá Fjöllum
Ódáðahraun
Jökuldals-heiði
Krafla60 MW
Bjarnarflag3 MW
Héraðs-flói
Brúar-öræfi
Vestur-öræfi
Askja
Herðu-breið
Krep
pa
Kverkfjöll Hraun
Dyngjujökull
Kröflulína 2132 kV
132 kV
132 kV
Kárahnjúkar HEP690 MW
Kára-hnjúkar
Headracetunnel
Jöku
lsáí F
ljótsd
al
Hálslónreservoir
KárahnjúkarPowerhouse
Kelduárlónreservoir
V A T N A J Ö K U L L G L A C I E R
BrúarjökullGlacier
Ufsarlónreservoir N
Kárahnjúkar HEP800 m a.s.l.
Pressure shaftHeadrace tunnel
Power station26,5
m a.s.l.
625 m a.s.l.Kárahnjúkar dam Longitude section
Mt. Fremri-Kárahnjúkur
Sauðárdalurdam
River Jökulsáá
Dal
Hafrahvammar Canyon
Desjarárdalur
Mt. KverkfjöllVatnajökull glacier
Kárahnjúkardam
Desjará dam
Hálslónreservoir
Installed capacity 690 MWNumber of units 6 (115 MW each)Energy production 4.6 TWhGross head 600 mRated discharge 144 m3/sHeight of Kárahnjúkar dam 200 mHálslón reservoir 57 km²Hálslón storage 2100 GlAll tunnels 73 kmHeadrace tunnel (diameter) 7.2-7.6 mConstruction time 2003-2008
Kárahnjúkar Project in figures
Spillway
Upstream cofferdam
Concrete Slab
Road
Rock protection
Diversion tunnel
Toe WallBottom outlet intake
Access tunnel
Bottom outlet
Kárahnjúkar dam
ca 100 m
Kárahnjúkar Dam Cross Section
Kárahnjúkar Dam Schematic Longitudinal View
Concrete Slab
Upstream cofferdam
Toe Wall
RCC concrete
Material 1
Material 4
Material 5A
Material 5B and 6A
Material 8
Concrete Slab
Toe Wall
Consolidation Grouting
Grout Curtain
Spillway and Tunnels
Jöku
lsáí
Fljót
sdal
Jöku
lsáí
Fljót
sdal
Lagarfljót
TeigsbjargTeigsbjarg
ValþjófsstaðurValþjófsstaður
PenstockPenstock
PowerhouseFljótsdalsstöðPowerhouseFljótsdalsstöð
Adit 1Adit 1
Headracetunnel
Headracetunnel
Tailracetunnel
Tailracetunnel
Tailrace-canal
Tailrace-canal
Surgeshaft
Surgeshaft
Kárahnjúkar HEP Powerhouse area
AdittunnelAdit
tunnel
Kárahnjúkar HEPPowerhouse area
Substation
Tailrace tunnel
Entrance buildingCable tunnel
Access tunnel
Fljótsdalsstöðpowerhouse
Pressure shafts
Transformer hall
Valve chamber (intake)
Jökulsá í Fljótsdal
Tailracecanal
TBM 1TBM 2TBM 3Drill & Blast 1Drill & Blast 2Drill & Blast 3Drill & Blast 4Drill & Blast 5Drill & Blast 6
5 km
10 km
15 km
20 km
25 km
30 km
35 km
Adit 1
Adit 2
Adit 3Adit 4
Power intake
Surge tunnel
Drainagetunnel
Jökulsá diversion tunnelø 7,2 m
Headrace tunnelø 7,6 m
Headrace tunnelø 7,2 m
Tunnel alignment
TBM 3
TBM 2TBM 1
Geology
• Shallow dipping strata(3 to 5°)
• Basalt flows with sediments and móberg formations in between
• Móberg is volcanic rock formed in water or glacical environment
• Faults & dykes at ~200 m spacing
Lithology
• Each basalt lava flow is divided into three parts:– Top scoria (10-30% of the thickness)
– Dense crystalline middle part (65-85% of the thickness) – tholeiitic or olivine
– Bottom scoria (5-10% of the thickness)
• Thin sedimentary layers between lava flow (typically 0,1 to 1m)
Sediment
Lava flow
Sediment
Excavation classes (D&B and TBM)
• Typical cross-sections on Drawings
• Excavation classes based on hindrance to advance
• Determination of excavation class using measurable criteria (i.e. nos. of rockbolts, extent of sprayed concrete)
• Risk associated with geological conditions with Owner
Bore classes
Scoria/Móberg >90%
H1 H2 H3 M1 M2
Sediments >90% <10% >50%
& <50%
<90%
>10% >50%
Basalt <10% <10% >90% & &
<50% <90%
Homogenous Face Mixed Face
Construction
− Robbins TBM
− Challenges encountered
− Mitigation measures
− Actual progress
− Utilization
Robbins TBMs
7,2 m dia 2 no7,6 m dia 1 noMotors 10Power Each 300 kWMax Thrust 14.305 kNStroke 1,87 mCutterhead speed 0-8,3 rpmCutters 47-49Size 483 mmMax load/cutter 311 kNTBM weight 600 tonCutterhead torque 6.275 kNm at 50 HzGripper load 3500 ton
Challenges encountered
• Red sedimentary layers, HRT 1
• Fault zone, HRT 2
• High water inflow, HRT 3
Fault zone, TBM 2, Headrace Tunnel
Fault #1 Fault #2 Fault #3
Steal arches& shotcrete
43 m
Concretebackfill80 m3
Concretebackfill120 m3
Concretebackfill 600 m3
Consolidation of rock withpolyurethan and cement
Void
CutterHead
Waterinflow
Waterinflow
• TBM3 turned around
• Adit 4
• Vertical pump & concrete shafts
• Revised design
• Reschedule finishing works
Mitigation measures
TBM 1TBM 2TBM 3Drill & Blast 1Drill & Blast 2Drill & Blast 3Drill & Blast 4Drill & Blast 5Drill & Blast 6
5 km
10 km
15 km
20 km
25 km
30 km
35 km
Adit 1
Adit 2
Adit 3Adit 4
Power intake
Surge tunnel
Drainagetunnel
Jökulsá diversion tunnelø 7,2 m
Headrace tunnelø 7,6 m
Headrace tunnelø 7,2 m
Tunnel alignment
TBM 3
TBM 2TBM 1
Utilization – TBM 1Between dates: 21.09.2004 - 09.09.2006
Cuttlers = Cutter Change + Cutter CheckTBM = TBM Maintenance + TBM Mech. Breakdown + TBM Elec. BreakdownUtilities = Conveyor Install + Conveyor Repairs + Service ExtensionOther + Cutter Cleaning + Downtime + Other + HolidayProbing Time also includes time for CoringGrouting Activities are under Other
Based on 24 days
BoringRegripSupportCuttersRepair TBMRepair BUSUtilitiesProbingOther
28.4%
0.4%
3.9%5.8%
2.1%
13.2%
6.7%
3.6%
35.8%
43%5%
10%5%7%4%6%9%
11%
TypicalPredicted
values
Utilization – TBM 2Between dates: 08.10.2004 - 28.09.2006
Cuttlers = Cutter Change + Cutter CheckTBM = TBM Maintenance + TBM Mech. Breakdown + TBM Elec. BreakdownUtilities = Conveyor Install + Conveyor Repairs + Service ExtensionOther + Cutter Cleaning + Downtime + Other + HolidayProbing Time also includes time for CoringGrouting Activities are under Other
Based on 24 days
BoringRegripSupportCuttersRepair TBMRepair BUSUtilitiesProbingOther
30.8%
1.2%15.1% 4.7%
7.2% 14.9%
2.3%
20.6%43%
5%10%
5%7%4%6%9%
11%
TypicalPredicted
values
3.3%
Utilization – TBM 2Between dates: 08.10.2004 - 28.09.2006
without 6 months EOT section
Cuttlers = Cutter Change + Cutter CheckTBM = TBM Maintenance + TBM Mech. Breakdown + TBM Elec. BreakdownUtilities = Conveyor Install + Conveyor Repairs + Service ExtensionOther + Cutter Cleaning + Downtime + Other + HolidayProbing Time also includes time for CoringGrouting Activities are under Other
Based on 24 days
BoringRegripSupportCuttersRepair TBMRepair BUSUtilitiesProbingOther
22.7%
5.5%1.3% 4.0%
19.4%
3.0%4.9%
27.3%43%
5%10%
5%7%4%6%9%
11%
TypicalPredicted
values
11.8%
Utilization – TBM 3 usBetween dates: 02.08.2004 - 07.07.2005
Cuttlers = Cutter Change + Cutter CheckTBM = TBM Maintenance + TBM Mech. Breakdown + TBM Elec. BreakdownUtilities = Conveyor Install + Conveyor Repairs + Service ExtensionOther + Cutter Cleaning + Downtime + Other + HolidayProbing Time also includes time for CoringGrouting Activities are under Other
Based on 24 days
BoringRegripSupportCuttersRepair TBMRepair BUSUtilitiesProbingOther
29.8%
8.3%
13.8% 2.1%
11.4%
3.0%
1.9%
22.1%43%
5%10%
5%7%4%6%9%
11%
TypicalPredicted
values
7.7%
Utilization – TBM 3 dsBetween dates: 19.12.2005 - 05.11.2006
Cuttlers = Cutter Change + Cutter CheckTBM = TBM Maintenance + TBM Mech. Breakdown + TBM Elec. BreakdownUtilities = Conveyor Install + Conveyor Repairs + Service ExtensionOther + Cutter Cleaning + Downtime + Other + HolidayProbing Time also includes time for CoringGrouting Activities are under Other
Based on 24 days
BoringRegripSupportCuttersRepair TBMRepair BUSUtilitiesProbingOther
13.1%
7.0%0.7% 5.1%
25.8%
3.4%
14.2%
27.2%43%
5%10%
5%7%4%6%9%
11%
TypicalPredicted
values
3.6%
Conclusions− First use of TBMs in Iceland− TBMs are generally well suited for
Icelandic mixed faced basaltic rock− Challenging ground
−Mixed face− Fault zones−Water ingress
− Conveyors can be effective for long, large diameter tunnel drives