SlideShare a Scribd company logo
1 of 49
FOUNDATIONS
INTRODUCTION TO FOUNDATIONS
 Function of a foundation is to transfer the structural loads
from a building safely into the ground.
 It should reach the underlying soil that is free of organic
matter and unreachable by the winter’s frost.
 A larger and heavier building of masonry, steel, or
concrete would require its foundations to go deeper into
earth such that the soil or the rock on which it is founded is
competent to carry its massive loads.
 foundation design is a highly specialized field of
geotechnical engineering.
2
Major Building Parts
Superstructure
Substructure
Foundation
Primary Factors Affecting
Foundation Choice
 Subsurface soil
 Ground water conditions
 Structural requirements
 Lateral earth pressure
 Intensity of loading
Secondary Factors Affecting Foundation
Choice
 Construction access, methods & site conditions
 Building Codes & Regulations
 Impact on surrounding structures
 Construction risks
 Environmental factors
SELECTION OF FOUNDATION TYPE
Selection of foundation depends on whether the load
is transfer at deeper depths or shallower depths.
Following parameters will be considered while
selecting a foundation type.
 Soil strength
 Ground conditions
 Foundation loads
 Construction methods
 Impact on adjacent property.
Foundation Loads
 Dead Load
 Live Load
 Wind Load
 Earthquake
 Structural Member Forces
SETTLEMENT IN FOUNDATION
 Uniform
 Differential
Differential settlement must be minimized, depends
on site soil conditions and distribution of loads on
columns supporting the building
SETTLEMENTS OF FOUNDATIONS
NO SETTLEMENT * TOTAL SETTLEMENT * DIFFERENTIAL SETTLEMENT
Uniform settlement is usually of little consequence in a building, but differential
settlement can cause severe structural damage
Main types of foundation
Foundations or ‘footings’ come under two main
categories
 Shallow foundation.
 Deep foundation.
Shallow foundations
Shallow foundations
Shallow foundations includes spread column footings without
or with tie/grade beams, individual or combined wall footing,
strip footings, stepped foundation, grillage foundation and
rafts.
The guidelines for a shallow foundation are
 They are founded near to the finished ground surface.
 The depth is generally less than the width of the footing
and less than 3m.
 They are used when the surface soils are strong enough to
support the load imposed upon it.
SPREAD FOOTINGS
 Made from reinforced concrete
– Square (B x B)-Usually one column
– Rectangular (B x L)-When large M is needed
– Circular (D/B<3, Rounded)-Flagpoles, transmission lines
– Continuous (Strip)-Support of bearing walls
– Combined (Cantilever)-Provides necessary M to prevent
failure. Desirable when load is eccentric and construction
close to property line.
Weight Distribution in footing
Sizes of Footings
 The width of the wall is the
height of the footing
 The width of the footing is
twice the size at the wall
 W, W, 2W is the rule
Footing Specifications
 Footings should extend down at least 6” into
undisturbed earth…no fillings under footing
 Footing must be at least 6” below the frost
line
 If soil is bad, increase the size of footing
Sizes of Foundation Walls
 Depends on lateral earth pressure and vertical
load to be supported
– Typically walls are 8” thick
 Basement walls must extend 8” above the
finished grade. Min height is 7’5”.
18
Combination Spread & Strip Footing Spread Footing
Spread FootingReinforcement in Spread Footing
19
Types of Spread Footing
20
21
Grillage Foundation
22
Steped Foundation
Strip foundations
These are use to support
a line of loads such as a
load bearing wall.
They could also be used
where the line of
column positions are so
close that individual pad
foundations would be
pointless.
Raft Foundations
 These are used to spread
the load from a structure
over a large area.
 This would normally be
the entire area of the
structure.
 Raft foundations are often
needed on soft or loose
soils which have a low
load bearing capacity.
ADVANTAGES OF RAFT FOUNDATIONS
– Spread the load in a larger area-Increase bearing pressure
– Provides more structural rigidity
– Reduce settlement
– Heavier-More resistant to uplift
– Distributes loads more evenly
Deep foundations
Deep foundations
 Shallow foundations are unsuitable in weak or highly
compressible soils so, deep foundation is provided in such
areas where soil bearing capacity is very low and heavy
loads are expected. Deep foundations are usually at depths
deeper than 3m and use to transmit the loading to a deeper,
more competent strata.
 Caissons with or without sockets, end bearing or friction
piles, pile walls and piers.
 Made of concrete (precast or cast in situ) or steel or wood
Deep Foundations - Purpose
transfer building loads deep into the earth
Basic types
– Drilled (& poured)
– Driven
(End bearing piles for
point load and friction piles
will transfer load by friction
resistance between the pile
and the earth)
Pile foundations
 Piles are used to support
buildings in poor soil
conditions.
 A basic pile foundation is a
series of stilts which rest on
a solid load bearing layer.
Precast Concrete Plies
Benched Excavation
Backhoe
34
DOZERS
Solder Beam & Lagging
Bank Requiring a Retention System
Retention System Depends On:
 Proximity to Buildings
 Type of Soil
 Water Table Level
 Temporary or Permanent
 Cost - KEY Consideration
Dewatering
 A process of removing Water and/or lowering the
Water Table within a construction site
 Purpose: To Provide a Dry working platform -
(typically required by Code and Specification)
 If the Water Table is above the working platform;
Options:
» Keep water out
» Let water in & remove it
» Combination
SOIL TYPES
 The make up of the soil has a major
influence on the choice of foundation.
 A good soil type needs to be able to cope
with loadings.
 A good soil needs to drain water well.
 A poor soil type will shrink, swell or move
depending on the loads or conditions placed
upon it.
SILT
 Silty soil is found in flood plains or around
lakes.
 Silt holds water well and is soft when wet.
 Silty soil is not a very good foundation
material unless it has been compressed and
hardened, or has been dried out.
SANDY SOIL
 Sand is usually considered favourable from
the standpoint of foundation support.
 It can be a problem though usually due to
water.
 Water raising through a sand deposit can
create an unstable condition.
 Sandy soils can hold water.
CLAY
 Clay is composed rock particles ground
extremely fine or reduced by weathering.
 Clay soils normally contain water.
 Clay drains slowly and compresses when
foundations are placed upon them.
 Clay has a tendency to absorb water and
swell.
ClaysPorous
(sandy)
GRAVEL
 Gravel can be well compacted and allows
water to drain freely.
 Gravel soils do not hold water.
 The variety in particle sizes in gravel means
that even when closely packed it still
contains voids and drains well.
 Gravel is least likely to be affected by
drying out.
Waterproofing
 Structures Below Ground subject to penetration of
ground water
 More extreme, if below H2O table
 Two basic approaches to Waterproofing
– Waterproof Membranes, or
– Drainage
– Generally - both used in tandem
Waterproofing Membranes
 Materials
– Liquid or Sheet (Plastic, asphaltic, synthetic rubber)
– Coatings (asphaltic)
– Cementitious Plasters & admixtures
 Accessories
– Protection Board
– Waterstop
 Unit of Measure - SF, Mils (thickness)
Thank You
49

More Related Content

What's hot (20)

Shallow foundation
Shallow foundationShallow foundation
Shallow foundation
 
Special Concretes
Special Concretes Special Concretes
Special Concretes
 
DEEP FOUNDATION
DEEP FOUNDATIONDEEP FOUNDATION
DEEP FOUNDATION
 
Foundation
FoundationFoundation
Foundation
 
Shallow foundation
Shallow foundationShallow foundation
Shallow foundation
 
Damp Proof Course
Damp Proof Course Damp Proof Course
Damp Proof Course
 
Pile foundation ppt
Pile foundation pptPile foundation ppt
Pile foundation ppt
 
TYPES OF PILE FOUNDATION & APPLICATIONS
TYPES OF PILE FOUNDATION & APPLICATIONSTYPES OF PILE FOUNDATION & APPLICATIONS
TYPES OF PILE FOUNDATION & APPLICATIONS
 
TYPES OF FOUNDATION(PPT)
TYPES OF FOUNDATION(PPT)TYPES OF FOUNDATION(PPT)
TYPES OF FOUNDATION(PPT)
 
Grouting
GroutingGrouting
Grouting
 
Chapter 3 building foundation
Chapter 3 building foundationChapter 3 building foundation
Chapter 3 building foundation
 
Coffer dam and its type
Coffer dam and its typeCoffer dam and its type
Coffer dam and its type
 
Shallow foundations
Shallow foundationsShallow foundations
Shallow foundations
 
Retaining wall - design of reinforced concrete structure
Retaining wall - design of reinforced concrete structureRetaining wall - design of reinforced concrete structure
Retaining wall - design of reinforced concrete structure
 
Chapter 3 shallow foundations
Chapter 3 shallow foundationsChapter 3 shallow foundations
Chapter 3 shallow foundations
 
Foundation ppt
Foundation pptFoundation ppt
Foundation ppt
 
Foundation
FoundationFoundation
Foundation
 
Footing and Its Types
Footing and Its TypesFooting and Its Types
Footing and Its Types
 
Bridge foundation
Bridge foundationBridge foundation
Bridge foundation
 
Foundation Engineering
Foundation EngineeringFoundation Engineering
Foundation Engineering
 

Viewers also liked

Types Of Foundation
Types Of FoundationTypes Of Foundation
Types Of Foundationstooty s
 
Footing design(09.02.03.096)
Footing design(09.02.03.096)Footing design(09.02.03.096)
Footing design(09.02.03.096)Zawad khalil
 
types of Foundations with animated sketches
types of Foundations with animated sketchestypes of Foundations with animated sketches
types of Foundations with animated sketchesGiri Babu S V
 
"A Review of the Settlement of Stone Columns in Compressible Soils"
"A Review of the Settlement of Stone Columns in Compressible Soils""A Review of the Settlement of Stone Columns in Compressible Soils"
"A Review of the Settlement of Stone Columns in Compressible Soils"Remedy Geotechnics Ltd
 
Foundation
FoundationFoundation
Foundationer_kamal
 
GSM fundamentals
GSM fundamentalsGSM fundamentals
GSM fundamentalstushar05
 
Com346 grossology case presentation
Com346 grossology case presentationCom346 grossology case presentation
Com346 grossology case presentationWeston Suggs
 
Com346 grossology case presentation
Com346 grossology case presentationCom346 grossology case presentation
Com346 grossology case presentationWeston Suggs
 
Essay 3 sergei eisenstein cinematic principle & ideogram
Essay 3 sergei eisenstein cinematic principle & ideogramEssay 3 sergei eisenstein cinematic principle & ideogram
Essay 3 sergei eisenstein cinematic principle & ideogramRyan Wariki
 
Matura2014 liceum plastyczne_koszalin
Matura2014 liceum plastyczne_koszalinMatura2014 liceum plastyczne_koszalin
Matura2014 liceum plastyczne_koszalinplastyk
 
Magfúzió
MagfúzióMagfúzió
Magfúziótaxy223
 
Dentistry @ Its Finest
Dentistry @ Its FinestDentistry @ Its Finest
Dentistry @ Its FinestMichael Ayzin
 
20150522_Woobe_Information Kit_Light
20150522_Woobe_Information Kit_Light20150522_Woobe_Information Kit_Light
20150522_Woobe_Information Kit_LightVincent Lebunetel
 

Viewers also liked (20)

Types Of Foundation
Types Of FoundationTypes Of Foundation
Types Of Foundation
 
Footing design(09.02.03.096)
Footing design(09.02.03.096)Footing design(09.02.03.096)
Footing design(09.02.03.096)
 
types of Foundations with animated sketches
types of Foundations with animated sketchestypes of Foundations with animated sketches
types of Foundations with animated sketches
 
"A Review of the Settlement of Stone Columns in Compressible Soils"
"A Review of the Settlement of Stone Columns in Compressible Soils""A Review of the Settlement of Stone Columns in Compressible Soils"
"A Review of the Settlement of Stone Columns in Compressible Soils"
 
Foundation
FoundationFoundation
Foundation
 
Tos ppt foundation
Tos ppt foundationTos ppt foundation
Tos ppt foundation
 
GSM fundamentals
GSM fundamentalsGSM fundamentals
GSM fundamentals
 
001cclass 120926194905-phpapp02
001cclass 120926194905-phpapp02001cclass 120926194905-phpapp02
001cclass 120926194905-phpapp02
 
Com346 grossology case presentation
Com346 grossology case presentationCom346 grossology case presentation
Com346 grossology case presentation
 
Com346 grossology case presentation
Com346 grossology case presentationCom346 grossology case presentation
Com346 grossology case presentation
 
Essay 3 sergei eisenstein cinematic principle & ideogram
Essay 3 sergei eisenstein cinematic principle & ideogramEssay 3 sergei eisenstein cinematic principle & ideogram
Essay 3 sergei eisenstein cinematic principle & ideogram
 
Обзор C# WPF MVVM
Обзор C# WPF MVVMОбзор C# WPF MVVM
Обзор C# WPF MVVM
 
Coad slide show
Coad slide showCoad slide show
Coad slide show
 
Matura2014 liceum plastyczne_koszalin
Matura2014 liceum plastyczne_koszalinMatura2014 liceum plastyczne_koszalin
Matura2014 liceum plastyczne_koszalin
 
Magfúzió
MagfúzióMagfúzió
Magfúzió
 
Haykinver4
Haykinver4 Haykinver4
Haykinver4
 
Algorithmiin shinjilgee
Algorithmiin shinjilgeeAlgorithmiin shinjilgee
Algorithmiin shinjilgee
 
Dentistry @ Its Finest
Dentistry @ Its FinestDentistry @ Its Finest
Dentistry @ Its Finest
 
51asd
51asd51asd
51asd
 
20150522_Woobe_Information Kit_Light
20150522_Woobe_Information Kit_Light20150522_Woobe_Information Kit_Light
20150522_Woobe_Information Kit_Light
 

Similar to Foundation 1 (20)

Chapter 4 deep foundation ( bi )
Chapter 4 deep foundation ( bi )Chapter 4 deep foundation ( bi )
Chapter 4 deep foundation ( bi )
 
Building foundation: Types, Conditions, and Safety Precautions
Building foundation: Types, Conditions, and Safety PrecautionsBuilding foundation: Types, Conditions, and Safety Precautions
Building foundation: Types, Conditions, and Safety Precautions
 
Foundation and its types
Foundation and its typesFoundation and its types
Foundation and its types
 
LECT 6 UPDATE.pdf
LECT  6 UPDATE.pdfLECT  6 UPDATE.pdf
LECT 6 UPDATE.pdf
 
Building components
Building componentsBuilding components
Building components
 
Foundation
FoundationFoundation
Foundation
 
foundation.pptx
foundation.pptxfoundation.pptx
foundation.pptx
 
Foundation
FoundationFoundation
Foundation
 
Ct presentation slide nah
Ct presentation slide nahCt presentation slide nah
Ct presentation slide nah
 
Tos ppt foundation1
Tos ppt foundation1Tos ppt foundation1
Tos ppt foundation1
 
LECT 5 UPDATE.pdf
LECT 5 UPDATE.pdfLECT 5 UPDATE.pdf
LECT 5 UPDATE.pdf
 
CONSTRUCTION OF MULTI STOREY BUILDING.pptx
CONSTRUCTION OF MULTI STOREY BUILDING.pptxCONSTRUCTION OF MULTI STOREY BUILDING.pptx
CONSTRUCTION OF MULTI STOREY BUILDING.pptx
 
Vs types of footings vandana miss
Vs types of footings vandana missVs types of footings vandana miss
Vs types of footings vandana miss
 
Foundations grp 1
Foundations grp 1Foundations grp 1
Foundations grp 1
 
shallow foundation, types and factor
shallow foundation, types and factorshallow foundation, types and factor
shallow foundation, types and factor
 
Foundation
FoundationFoundation
Foundation
 
CHAPTER-2.1 FOUNDATIONS.ppt
CHAPTER-2.1 FOUNDATIONS.pptCHAPTER-2.1 FOUNDATIONS.ppt
CHAPTER-2.1 FOUNDATIONS.ppt
 
Civil types of foundations for different soil characteristics (2) - copy
Civil types of foundations for different soil characteristics (2) - copyCivil types of foundations for different soil characteristics (2) - copy
Civil types of foundations for different soil characteristics (2) - copy
 
Unit 3
Unit 3Unit 3
Unit 3
 
Chapter 3
Chapter 3Chapter 3
Chapter 3
 

Foundation 1

  • 2. INTRODUCTION TO FOUNDATIONS  Function of a foundation is to transfer the structural loads from a building safely into the ground.  It should reach the underlying soil that is free of organic matter and unreachable by the winter’s frost.  A larger and heavier building of masonry, steel, or concrete would require its foundations to go deeper into earth such that the soil or the rock on which it is founded is competent to carry its massive loads.  foundation design is a highly specialized field of geotechnical engineering. 2
  • 4. Primary Factors Affecting Foundation Choice  Subsurface soil  Ground water conditions  Structural requirements  Lateral earth pressure  Intensity of loading
  • 5. Secondary Factors Affecting Foundation Choice  Construction access, methods & site conditions  Building Codes & Regulations  Impact on surrounding structures  Construction risks  Environmental factors
  • 6. SELECTION OF FOUNDATION TYPE Selection of foundation depends on whether the load is transfer at deeper depths or shallower depths. Following parameters will be considered while selecting a foundation type.  Soil strength  Ground conditions  Foundation loads  Construction methods  Impact on adjacent property.
  • 7. Foundation Loads  Dead Load  Live Load  Wind Load  Earthquake  Structural Member Forces
  • 8. SETTLEMENT IN FOUNDATION  Uniform  Differential Differential settlement must be minimized, depends on site soil conditions and distribution of loads on columns supporting the building
  • 9. SETTLEMENTS OF FOUNDATIONS NO SETTLEMENT * TOTAL SETTLEMENT * DIFFERENTIAL SETTLEMENT Uniform settlement is usually of little consequence in a building, but differential settlement can cause severe structural damage
  • 10.
  • 11. Main types of foundation Foundations or ‘footings’ come under two main categories  Shallow foundation.  Deep foundation.
  • 12. Shallow foundations Shallow foundations Shallow foundations includes spread column footings without or with tie/grade beams, individual or combined wall footing, strip footings, stepped foundation, grillage foundation and rafts. The guidelines for a shallow foundation are  They are founded near to the finished ground surface.  The depth is generally less than the width of the footing and less than 3m.  They are used when the surface soils are strong enough to support the load imposed upon it.
  • 13. SPREAD FOOTINGS  Made from reinforced concrete – Square (B x B)-Usually one column – Rectangular (B x L)-When large M is needed – Circular (D/B<3, Rounded)-Flagpoles, transmission lines – Continuous (Strip)-Support of bearing walls – Combined (Cantilever)-Provides necessary M to prevent failure. Desirable when load is eccentric and construction close to property line.
  • 15. Sizes of Footings  The width of the wall is the height of the footing  The width of the footing is twice the size at the wall  W, W, 2W is the rule
  • 16. Footing Specifications  Footings should extend down at least 6” into undisturbed earth…no fillings under footing  Footing must be at least 6” below the frost line  If soil is bad, increase the size of footing
  • 17. Sizes of Foundation Walls  Depends on lateral earth pressure and vertical load to be supported – Typically walls are 8” thick  Basement walls must extend 8” above the finished grade. Min height is 7’5”.
  • 18. 18 Combination Spread & Strip Footing Spread Footing Spread FootingReinforcement in Spread Footing
  • 20. 20
  • 23. Strip foundations These are use to support a line of loads such as a load bearing wall. They could also be used where the line of column positions are so close that individual pad foundations would be pointless.
  • 24. Raft Foundations  These are used to spread the load from a structure over a large area.  This would normally be the entire area of the structure.  Raft foundations are often needed on soft or loose soils which have a low load bearing capacity.
  • 25. ADVANTAGES OF RAFT FOUNDATIONS – Spread the load in a larger area-Increase bearing pressure – Provides more structural rigidity – Reduce settlement – Heavier-More resistant to uplift – Distributes loads more evenly
  • 26. Deep foundations Deep foundations  Shallow foundations are unsuitable in weak or highly compressible soils so, deep foundation is provided in such areas where soil bearing capacity is very low and heavy loads are expected. Deep foundations are usually at depths deeper than 3m and use to transmit the loading to a deeper, more competent strata.  Caissons with or without sockets, end bearing or friction piles, pile walls and piers.  Made of concrete (precast or cast in situ) or steel or wood
  • 27. Deep Foundations - Purpose transfer building loads deep into the earth Basic types – Drilled (& poured) – Driven (End bearing piles for point load and friction piles will transfer load by friction resistance between the pile and the earth)
  • 28. Pile foundations  Piles are used to support buildings in poor soil conditions.  A basic pile foundation is a series of stilts which rest on a solid load bearing layer.
  • 29.
  • 30.
  • 31.
  • 36. Solder Beam & Lagging
  • 37. Bank Requiring a Retention System
  • 38. Retention System Depends On:  Proximity to Buildings  Type of Soil  Water Table Level  Temporary or Permanent  Cost - KEY Consideration
  • 39. Dewatering  A process of removing Water and/or lowering the Water Table within a construction site  Purpose: To Provide a Dry working platform - (typically required by Code and Specification)  If the Water Table is above the working platform; Options: » Keep water out » Let water in & remove it » Combination
  • 40. SOIL TYPES  The make up of the soil has a major influence on the choice of foundation.  A good soil type needs to be able to cope with loadings.  A good soil needs to drain water well.  A poor soil type will shrink, swell or move depending on the loads or conditions placed upon it.
  • 41. SILT  Silty soil is found in flood plains or around lakes.  Silt holds water well and is soft when wet.  Silty soil is not a very good foundation material unless it has been compressed and hardened, or has been dried out.
  • 42. SANDY SOIL  Sand is usually considered favourable from the standpoint of foundation support.  It can be a problem though usually due to water.  Water raising through a sand deposit can create an unstable condition.  Sandy soils can hold water.
  • 43. CLAY  Clay is composed rock particles ground extremely fine or reduced by weathering.  Clay soils normally contain water.  Clay drains slowly and compresses when foundations are placed upon them.  Clay has a tendency to absorb water and swell.
  • 45. GRAVEL  Gravel can be well compacted and allows water to drain freely.  Gravel soils do not hold water.  The variety in particle sizes in gravel means that even when closely packed it still contains voids and drains well.  Gravel is least likely to be affected by drying out.
  • 46. Waterproofing  Structures Below Ground subject to penetration of ground water  More extreme, if below H2O table  Two basic approaches to Waterproofing – Waterproof Membranes, or – Drainage – Generally - both used in tandem
  • 47. Waterproofing Membranes  Materials – Liquid or Sheet (Plastic, asphaltic, synthetic rubber) – Coatings (asphaltic) – Cementitious Plasters & admixtures  Accessories – Protection Board – Waterstop  Unit of Measure - SF, Mils (thickness)
  • 48.