Thermosyphon foundations
Thermosyphon foundations
Thermosyphon foundations
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Impact Of Climate Change On Structures<br />
On Permafrost<br />
Presented by Igor Holubec 2007 PMC<br />
Igor Holubec<br />
2007 Yellowknife PMC
Topics To Be Covered<br />
• Air temperature changes<br />
• Ground temperatures & permafrost<br />
• Permafrost<br />
• Dams & wastes on permafrost<br />
• Building <strong>foundations</strong><br />
• Effect of climate warming on <strong>foundations</strong><br />
• Foundation design options for climate<br />
warming<br />
Igor Holubec<br />
2007 Yellowknife PMC
Climate Warming In Northern<br />
Canada<br />
Air temperature changes<br />
Igor Holubec<br />
2007 Yellowknife PMC
Recent and Predicted Global<br />
Climate Warming<br />
IPCC 2007<br />
Igor Holubec<br />
2007 Yellowknife PMC
Global Mean Air Temperature Rise Trend<br />
Igor Holubec<br />
2007 Yellowknife PMC
Climate Warming In Inuvik<br />
-2<br />
INUVIK (68° 18' N, 133° 28'W, 68m<br />
Me ean Annual Air Temperat ture, deg C<br />
-4<br />
-6<br />
-8<br />
-10<br />
-12<br />
y = 0.0746x - 156.8<br />
Air temp -7.2°C<br />
Ground temp ~ - 2.8°C<br />
Ground temperature<br />
at 0°C<br />
Temperatures<br />
Ground=Air + 4.4ºC<br />
-14<br />
1940 1960 1980 2000 2020 2040 2060 2080 2100<br />
Igor Holubec<br />
2007 Yellowknife PMC
Ground Temperatures In Permafrost<br />
• Mean annual ground temperature is about<br />
4.4ºC warmer than<br />
mean annual air temperature<br />
• Present ground temperatures & its changes<br />
• Climate & ground temperature warming<br />
• Permafrost<br />
Igor Holubec<br />
2007 Yellowknife PMC
2006 MAGT from MAAT<br />
<br />
-6.0°<br />
-11.2°<br />
<br />
-2.8°<br />
<br />
-0.3°<br />
-2.4° <br />
<br />
-8.6°<br />
-5.0 50°<br />
<br />
<br />
<br />
+1.0°<br />
-4.9°<br />
<br />
-6.3°<br />
-5.5°<br />
-9.4° -2.3°<br />
<br />
<br />
-2.9°<br />
+0.9 9°<br />
<br />
Igor Holubec<br />
CONTINUOUS PERMAFROST<br />
EXTENSIVE PERMAFROST<br />
SPORADIC PERMAFROST<br />
NRC Permafrost Map<br />
MCR 4177FF, 1995<br />
2007 Yellowknife PMC
As Permafrost Warms<br />
Permafrost warms >-2ºC<br />
• Weak ground – instability<br />
• Pile <strong>foundations</strong> heave & settle<br />
• Dams without thermosyphon will start to seep<br />
Permafrost ≥ 0ºC<br />
• Slope sloughing & instability<br />
• Ice melts – thaw settlement<br />
• Ice melts<br />
– seepage through sands, gravels<br />
and rock fractures<br />
Igor Holubec<br />
2007 Yellowknife PMC
Ground Temperature Changes<br />
0<br />
-20 -16 -12 -8 -4 0 4 8 12<br />
2<br />
4<br />
Dep pth, m<br />
6<br />
8<br />
10<br />
12<br />
14<br />
Jun o1<br />
Jul-01<br />
Aug-01<br />
Sep-01<br />
Oct-01<br />
Nov-01<br />
Dec-01<br />
Mean Annual<br />
Jan-02<br />
Feb-02<br />
Ground Temperature<br />
Mar-02<br />
16<br />
Igor Holubec<br />
2007 Yellowknife PMC
Ground Temperatures At Inuvik<br />
Air temperature, deg C<br />
-10 -8 -6 -4 -2 0 2 4<br />
0<br />
2<br />
4<br />
6<br />
Depth, m<br />
8<br />
10<br />
12<br />
19-Nov-06<br />
10-Feb-07<br />
09-Mar-07<br />
11-Jun-07<br />
14<br />
Igor Holubec<br />
2007 Yellowknife PMC
Time Relation Between Air & Ground<br />
Temperature<br />
14 20<br />
C<br />
Ground tem mperature, deg<br />
12<br />
10<br />
8<br />
6<br />
4<br />
2<br />
0<br />
-2<br />
-4<br />
-6<br />
<br />
-3.3°C<br />
+13°C<br />
Ground temperature<br />
at 3.5m depth<br />
Mean monthly air temperature<br />
<br />
-1.2°C<br />
<br />
-26°C<br />
6-May-02 5-Jul-02 3-Sep-02 2-Nov-02 1-Jan-03 2-Mar-03 1-May-03<br />
10<br />
0<br />
-10<br />
-20<br />
-30<br />
, deg C<br />
r temperature,<br />
Mea an monthly ai<br />
Igor Holubec<br />
2007 Yellowknife PMC
Forms Of Ice Permafrost<br />
ICE WEDGES<br />
ICE RICH SOIL<br />
PALSAS<br />
MASSIVE<br />
ICE LENSES<br />
ICE IN<br />
ROCK FRACTURES<br />
ICE FORMS<br />
Igor Holubec<br />
2007 Yellowknife PMC
Permafrost Terrain Types<br />
Igor Holubec<br />
2007 Yellowknife PMC
Excavation at Aurora College, Inuvik<br />
2.6m<br />
Igor Holubec<br />
2007 Yellowknife PMC
Climate Warming Rate<br />
• Not an exact science<br />
Two methods<br />
• Computer models – related to<br />
estimates of future green house gases<br />
projections<br />
• Extend recent linear air temperature<br />
trends<br />
Igor Holubec<br />
2007 Yellowknife PMC
Summary of MAGT & its Warming<br />
based on linear trends<br />
Region<br />
Western Arctic & Arctic<br />
Mackenzie Valley<br />
Central Mainland Arctic<br />
2006 MAGT Mean warming<br />
Range rate deg C°/10<br />
deg C<br />
yr<br />
1 to -3 0.6<br />
-5 to -6 a 11<br />
Eastern Arctic 1 to -3 17<br />
Arctic Islands -8 to -12 9<br />
Igor Holubec<br />
2007 Yellowknife PMC
As Permafrost Warms<br />
Permafrost warms >-2ºC<br />
• Weak ground – instability<br />
• Pile <strong>foundations</strong> heave & settle<br />
• Dams without thermosyphon will start to seep<br />
Permafrost ≥ 0ºC<br />
• Slope sloughing & instability<br />
• Ice melts – thaw settlement<br />
• Ice melts<br />
– seepage through sands, gravels<br />
and rock fractures<br />
Igor Holubec<br />
2007 Yellowknife PMC
DESIGN CRITERIA IN PERMAFROST<br />
GROUND TEMPERATURE DEPENDENT<br />
For dams<br />
Frozen <strong>foundations</strong><br />
Maximum ground temperature - 2ºC<br />
For Pile Foundation<br />
Maximum ground temperature - 2ºC<br />
Igor Holubec<br />
2007 Yellowknife PMC
Vulnerability of Structures on<br />
Permafrost<br />
Type<br />
Mine Wastes<br />
Dams<br />
Degree & Time<br />
High – 40 to 80 years<br />
High – 20 to 50 years<br />
Building Foundations Medium – present &<br />
near future<br />
Roads & Pipelines Medium to low –<br />
present & near future<br />
Igor Holubec<br />
2007 Yellowknife PMC
Dams & Waste Storage<br />
• Design<br />
• Impact of climate warming<br />
• Potential ti modifications<br />
Igor Holubec<br />
2007 Yellowknife PMC
Dam Design On Frozen Ground<br />
LINER<br />
ROCKFILL<br />
DAM<br />
THAWED<br />
GROUND<br />
<br />
<br />
<br />
PERMAFROST<br />
THERMOSYPHON COOLING<br />
Igor Holubec<br />
2007 Yellowknife PMC
Selected Dams in NU & NT<br />
Lupin Mine (1981)<br />
Ekati Mine, Outlet Dam (1998)<br />
Igor Holubec<br />
Diavik Mine, Sediment Pond (2000)<br />
2007 Yellowknife PMC
Dam Failures & Dump Erosion<br />
Igor Holubec<br />
2007 Yellowknife PMC
Dam Design Concepts<br />
LINER<br />
••••<br />
FROZEN<br />
THERMOSYPHON PIPES<br />
PERMAFROST REGIONS<br />
NO SEEPAGE<br />
FILL<br />
CLAY ZONE<br />
DRAINAGE<br />
BLANKET<br />
SEEPAGE<br />
WARM REGIONS<br />
Igor Holubec<br />
2007 Yellowknife PMC
Solid Waste Storage In Permafrost<br />
Tailings<br />
Landfills<br />
Mine rock dumps<br />
Igor Holubec<br />
2007 Yellowknife PMC
Short-term Design<br />
Preserve frozen foundation<br />
Some Long-term Design<br />
• Dams – breach or design for non-permafrost<br />
condition<br />
• Buildings – Dismantle at end of life span<br />
• Mine and municipal wastes – Durable slow<br />
erosion covers – minimize surface water<br />
erosion<br />
Igor Holubec<br />
2007 Yellowknife PMC
Foundations in Permafrost<br />
• Historic foundation designs<br />
• Temp design criterion<br />
• Performance<br />
• Design options for <strong>foundations</strong> in<br />
warming/thawing permafrost<br />
– Thick granular pad<br />
– Deep <strong>foundations</strong><br />
– <strong>Thermosyphon</strong> passive cooling<br />
Igor Holubec<br />
2007 Yellowknife PMC
Historic Foundations<br />
Igor Holubec<br />
2007 Yellowknife PMC
Slurry Pile In Frozen Ground<br />
Drill hole<br />
Install pile<br />
Place wet sand<br />
and allow to freeze<br />
Igor Holubec<br />
2007 Yellowknife PMC
Common Foundation Design<br />
BUILDING<br />
PILES<br />
AIR SPACE<br />
PERMAFROST<br />
Igor Holubec<br />
2007 Yellowknife PMC
Pile Foundation Failures As<br />
Permafrost Warms<br />
Igor Holubec<br />
2007 Yellowknife PMC
Annual Ground Temperature Fluctuations<br />
0<br />
-20 -16 -12 -8 -4 0 4 8 12<br />
2<br />
4<br />
De epth, m<br />
6<br />
8<br />
10<br />
12<br />
14<br />
Jun o1<br />
Jul-01<br />
Aug-01<br />
Sep-01<br />
Oct-01<br />
Nov-01<br />
Dec-01<br />
Jan-02<br />
Feb-02<br />
Mar-02<br />
16<br />
Igor Holubec<br />
2007 Yellowknife PMC
Critical Ground Temperature Profiles<br />
Ground temperatures, deg C<br />
-20 -16 -12 -8 -4 0 4 8<br />
0<br />
2<br />
4<br />
Max'm<br />
heave<br />
e<br />
potential<br />
Max'm<br />
settlement<br />
potential<br />
Depth,<br />
m<br />
6<br />
8<br />
10<br />
Oct-01<br />
Dec-01<br />
Maxium Design<br />
Groung Temp<br />
-2.0ºC<br />
12<br />
Igor Holubec<br />
2007 Yellowknife PMC
Slurry Pile In Frozen Ground<br />
September<br />
SETTLEMENT<br />
Thawed<br />
zone<br />
November<br />
HEAVE<br />
‘Cold’<br />
High strength<br />
ground<br />
heaves<br />
Igor Holubec<br />
‘Warm’<br />
Low strength<br />
Permafrost<br />
2007 Yellowknife PMC
Distress Signs – Walls & Doors<br />
Igor Holubec<br />
2007 Yellowknife PMC
Settlement, Pile Extension<br />
Igor Holubec<br />
2007 Yellowknife PMC
Pile Heave, Bending Of Beams<br />
Igor Holubec<br />
2007 Yellowknife PMC
Settlement Adjustments<br />
Igor Holubec<br />
2007 Yellowknife PMC
Foundations For Climate Warming<br />
• Thick granular pads<br />
• Deep piles into low ice soil<br />
• <strong>Thermosyphon</strong> <strong>foundations</strong><br />
Igor Holubec<br />
2007 Yellowknife PMC
Granular Pad Foundation<br />
Spoil<br />
organic layer<br />
Re-use thawed<br />
Drained soil<br />
~3 to 4m<br />
Thawed<br />
& refrozen<br />
zone<br />
~1m<br />
Igor Holubec<br />
2007 Yellowknife PMC
Deep Pipe Foundation<br />
~ 10m<br />
‘End’ bearing into<br />
low or non<br />
ice rich soil<br />
Grouted<br />
Igor Holubec<br />
2007 Yellowknife PMC
Ground Thaw In Warm Permafrost<br />
Region<br />
Igor Holubec<br />
2007 Yellowknife PMC
<strong>Thermosyphon</strong> Foundations<br />
• <strong>Thermosyphon</strong> Probes<br />
• Thermopiles<br />
• Sloped thermosyphon<br />
• Flat loop thermosyphon<br />
Igor Holubec<br />
2007 Yellowknife PMC
Flat Loop <strong>Thermosyphon</strong> Foundation<br />
Cambridge Bay School<br />
Igor Holubec<br />
2007 Yellowknife PMC
<strong>Thermosyphon</strong> Foundation Types<br />
BUILDING<br />
BUILDING<br />
BUILDING<br />
b) Sloping evaporator<br />
thermosyphon<br />
c) Flat looped evaporator<br />
thermosyphon<br />
a) Thermopile<br />
Igor Holubec<br />
2007 Yellowknife PMC
<strong>Thermosyphon</strong> Concept<br />
Gas<br />
HEAT OUT<br />
AIR<br />
cold<br />
GROUND<br />
warm<br />
COND<br />
DENSATE FLOW<br />
VAPOUR<br />
FLOW<br />
EVAPORA<br />
ATIO COND<br />
DENSATION<br />
Igor Holubec<br />
HEAT IN<br />
Liquid<br />
2007 Yellowknife PMC
Flat Loop <strong>Thermosyphon</strong> Concept<br />
HEAT OUT<br />
CONDENSER<br />
(RADIATOR)<br />
CONDENSATE<br />
FLOW<br />
VAPOUR FLOW<br />
FLUID<br />
EVAPORATOR PIPE<br />
VAPOUR<br />
HEAT IN<br />
Igor Holubec<br />
2007 Yellowknife PMC
Design Components Of Flat Loop<br />
Slab-on-grade <strong>Thermosyphon</strong> h Foundation<br />
RADIATOR<br />
CONDENSOR PIPE<br />
EVAPORATOR PIPE<br />
<br />
VALVE<br />
CONCRETE SLAB<br />
GRANULAR<br />
RIGID<br />
INSULATION<br />
BEDDING<br />
NON-FROST SUSCEPTIBLE<br />
GRANULAR BASE<br />
Igor Holubec<br />
2007 Yellowknife PMC
Flat Loop <strong>Thermosyphon</strong> Foundation<br />
THERMOSYPHON<br />
COOLING<br />
BUILDING<br />
INSULATION<br />
PERMAFROST<br />
Igor Holubec<br />
2007 Yellowknife PMC
Design Options<br />
RADIATORS<br />
FLOOR<br />
FLOOR<br />
GROUND<br />
BEAM<br />
CRAWL SPACE<br />
GRANULAR<br />
EVAPORATOR<br />
PIPES<br />
INSULATION<br />
a) Slab-on-grade b) Crawl-space<br />
Igor Holubec<br />
2007 Yellowknife PMC
Flat Loop <strong>Thermosyphon</strong> Foundation<br />
Igor Holubec<br />
2007 Yellowknife PMC
Solution - <strong>Thermosyphon</strong> Foundation<br />
Igor Holubec<br />
2007 Yellowknife PMC
Inuvik Hospital – Crawl Space Design<br />
Igor Holubec<br />
2007 Yellowknife PMC
Aurora College, Inuvik, NT<br />
Igor Holubec<br />
2007 Yellowknife PMC
Ground Temperatures With Time<br />
10<br />
Aurora College T5<br />
5<br />
2002<br />
2003 2004<br />
Ground tem mperature, deg C<br />
0<br />
-5<br />
-10<br />
-15<br />
Depth<br />
0<br />
10m 1.0m<br />
2.0m<br />
3.0m<br />
4.0m<br />
6.0m<br />
-20<br />
3-Jun-02 2-Sep-02 2-Dec-02 3-Mar-03 2-Jun-03 1-Sep-03 1-Dec-03 1-Mar-04 31-May-04 30-Aug-04<br />
Igor Holubec<br />
2007 Yellowknife PMC
Ground Temperatures With Time<br />
Ground temperature, deg C<br />
-12 -10 -8 -6 -4 -2 0 2 4 6 8<br />
0<br />
1<br />
Depth below evap portor pipes, m<br />
2<br />
3<br />
4<br />
5<br />
6<br />
19-Jul-02<br />
17-Sep-02<br />
20-Oct-02<br />
11-Dec-02<br />
07-Jan-03<br />
03<br />
17 May-03"<br />
15 Jul-03<br />
09-Dec-03<br />
Granular<br />
Fill<br />
Natural<br />
Ground<br />
Aurora College, T5<br />
7<br />
Igor Holubec<br />
2007 Yellowknife PMC
Number Of <strong>Thermosyphon</strong>s Installed<br />
In Canada Since 1985<br />
Region<br />
Number<br />
Nunavut 52<br />
Northwest Territory 41<br />
Manitoba 15<br />
Quebec 10<br />
Yukon 8<br />
Ontario 1<br />
Total 127<br />
Igor Holubec<br />
2007 Yellowknife PMC
PIEVC <strong>Thermosyphon</strong> Foundations<br />
In Warm Permafrost Study<br />
Assess performance of<br />
• Four case histories in Inuvik<br />
• Other case histories in Iqaluit,<br />
Pangnirtung, Kuujjuaq, Rankin Inlet<br />
and others<br />
Evaluate their potential as a<br />
foundation design for climate<br />
warming<br />
Performance risks during 50 year<br />
design live<br />
Igor Holubec<br />
2007 Yellowknife PMC
Conclusions<br />
• <strong>Thermosyphon</strong> design developed as a<br />
foundation for warm permafrost.<br />
• In general, they have been performing well<br />
and provided intended results.<br />
• There have been some problems.<br />
• Problems are related to un-coordinated<br />
design and poor construction schedule and<br />
control.<br />
Igor Holubec<br />
2007 Yellowknife PMC
Conclusions<br />
• There is a need to refine design for<br />
<strong>foundations</strong> for structure with design life of<br />
50 years and in climate warming scenario.<br />
• There is a need for guidelines in several<br />
areas.<br />
• There is a need to monitor the performance<br />
and likely periodic maintenance over the 50<br />
years design life of this type of foundation.<br />
Igor Holubec<br />
2007 Yellowknife PMC
Thaw will ruin their ride<br />
Igor Holubec<br />
2007 Yellowknife PMC
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