Final Presentation
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Transcript of Final Presentation
Foundations in permafrost soil
(BLDG 6501: FOUNDATION ENGINEERING)
Professor: Dr. Adel Hanna
Student ID
Hossein Khodaverdipoursarbandi 40003814
Introduction
Types of permafrost
Insulation Use
Foundation design
Final considerations
2
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
3
Permafrost:• Any soil that has remained continuously frozen for at least 2 years
Where to find?• In U.S.A , Canada and most industrialized nations of the world• Anywhere there is a freezer plant for cold storage ( a frozen
orange juice manufacturing facility)
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
4
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
5
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
6
Types of permafrost:• Thaw-stable: A soil whose water content is at saturation
or less (safe to build)• Thaw-unstable :
If the frozen soil’s moisture content is greater than saturation
additional space is required for the excess ice (water when it thaws)
When this soil thaws, soil grains sink until they are resting against each other
This overall consolidation= thaw-instability
Settlement of the surface and foundation failures
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
7
Outline
Introduction
Types of permafrost
Literature Review
Component Design
Energy Modeling
Wood-framed VS ICFs
Conclusion
References
8
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
9
Proper Materials for insulationMaterial Discription Benefits drawbacks
Fiberglass Most commonly modern
insulation material
High thermal resistance, relatively inexpensive, resist mold an
fungus ,easy to install
Little resistance to moisture
Foam polystyrene
(XEPS)
Widely used in construction
for intrusion water and in buried situation, high water resistance insulation, ability to maintain its
thickness under load
Very little losing thermal resistance at some adverse
applications
Molded polystyrene board (EPS)
A cohesive solid with variable
density
More water resistance than XEPS, Its voids provide a path to enter to the board and absorb water
Foamed polyurethane
Unique advantages for
special buildings
Ability of spraying makes it attractive for filling cracks and
sealing openings, stud spaces in pre-built wall sections, One of the
highest thermal resistance
Lower thermal conductivity before
aging, expensive, open-cell-
structure, easily damaged during
construction
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
10
Slurried Pile Foundation:• Developed conventional foundation• Piles embedded to permafrost• Piles extend above the surface to raise the building off the
ground (at least 2ft, 0.6m)• Adfreeze bond in the permafrost layer provides required
support for piles (heaving force)• Adfreeze bond in active layer can be eliminated by using
sleeves or coating on the piles• Expensive foundation but far less costly than remedial
actions
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
11
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
12
Driven piles:• Steel pipe piles driven into frozen soil• When soil is relatively dry, uniform ,fine grained material• Pile driving difficulty increases with decreasing soil tempreture Load capacity:• Long settlement of pile is called Creep• Pile should keep the secondary creep to prevent deformationPile lenghth• The depth of pile into permafrost should not be less than twice the
thickness of active layerAdfreeze bond strength calculation• The temperature dependant• Colder temperature = stronger adfreeze bondShallow foundation• When neither drilling nor driving equipment is available• Not as reliable as deep piles
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
13
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
14
Natural convection pile foundation:• To increase the rate of heat out of the soil• Enhancing the ability of permafrost to survive summer or
other increased heat input• Without the aid of external power • Classified as either 1.open or 2.closed (single-phase or
two phase)
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
15
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
16
Surface foundation:The post and pad foundation
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
17
Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
The adjustable post and pad foundation
Rigid three dimensional truss foundation
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Outline
Introduction
Types of permafrost
Insulation Use
Foundation Design
Final consideration
Air flow beneath the elevated foundation• all elevated foundations rely on free circulation of air
beneath the building to protect the permafrost• Preventing debris or snow to accumulate there• Skirting around the building can destroy the function of air
flow
The Surrounding Site• The surrounding area in the immediate vicinity of the
building must be cleared• The maintenance problems of water and sewer lines
connected to the building
Access to the site• The driveway connected to the building should be covered
by a thick layer of non-frost-susceptible fill and it is better to be on the north or northeast of the building (less sun)
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