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Prepared by :
Othman Hassan
Senior Lecturer / Registered Interior Designer with Lembaga Arkitek Malaysia (Reg. No: ID/O 6)
Department of Interior Architecture
UiTM Perak
c
FOUNDATIONS
INA105/151Building Construction & Materials 1
FOUNDATIONS INA105/151
The construction of foundation starts after all the tasks below completed.
1. Site Investigation2. Clearing the site3. Establishing level4. Setting out the building line
1. FOUNDATION AND ITS FUNCTIONS
1. As the base on which a building rests and its purpose is to safely transfer the load of a building to a suitable subsoil.2. Prevent possible movement of structure due to settlement (ground movement)3 Allow building over water or water-logged ground4.Resist uplifting or overturning forces due to wind5.Resist lateral forces due to soil movement6.Underpin (support) existing or unstable structures
2. FACTORS THAT INFLUENCE THE CHOICE OF FOUNDATION TYPE
The choice and design of foundations for many types of building depend mainly on factors below:
1. The total loads of the building2. The nature and bearing capacity of the soil.3. Materials used for the foundation4. Economical consideration of using a right kinds of foundation5. Layout of the structures (building/floor plan, positioning loads)6. Conditional of the site (location and sufficient work space)
FOUNDATIONS INA105/151
3. SUBSOIL AND BEARING CAPACITY
Subsoils are soils below the topsoil ; the topsoil being about 300mm deep from the ground level surface. Bearing capacity is safe load per unit area which the ground can carry.
Typical bearing capacities of subsoils are as follows:
Rock, granite 600 -10,000 kN/m2 (60,000-1,000,000kg)Non-cohesive soils, compact sand600 kN/m2
Cohesive soils, hard clay <600 kN/m2
Having ascertained the nature and bearing capacity of the subsoil the foundation can be determined by calculating the total (dead + imposed) load per meter run of foundation and relating this to the analyzed safe bearing capacity of the subsoil
Total load of building per meter = min. foundation widthSafe bearing capacity of subsoil
The average total loading for a two-storey house is 30-50 kN/m2
FOUNDATIONS INA105/151
3. SUBSOIL AND BEARING CAPACITY
Example: If the total load of a house is 40 kN/m2 and the subsoil safe bearing capacity is 80 kN/m2, then the foundation width is:
40 = 0.5 m or 500mm (strip foundation) 80
FOUNDATIONS INA105/151
SUBSOIL TYPE kN/m2
Hardpan overlaying rock 1290
Very compact sandy gravel 1075
Loose gravel and sandy gravel, compact sand and 645gravelly sand, very compact sand-inorganic silt soils
Hard, dry, consolidated clay 537
Loose coarse to medium sand, medium compact fine sand 430
Compact sand clay 322
Loose, fine sand, medium compact sand-inorganic silt soils 215
Firm or stiff clay 161
Loose, saturated sand-clay soils, medium soft clay 107
FOUNDATIONS INA105/151
3. SUBSOIL AND BEARING CAPACITY
High Bearing Capacity
MediumBearing Capacity
LowBearing Capacity
Under pure vertical downward loads
Wind
4. FORCES ACTING ONTO BUILDING
Under lateral wind loads Combined effect
Downward loadUplifting action
Tendency to turn under
wind
Building BuildingBuilding
FOUNDATIONS INA105/151
5. TYPES OF BUILDING FOUNDATION:
1. Shallow Foundation
a. Pad Foundation or Isolated Foundation
b. Raft Foundations - Solid Slab Raft Foundation
- Beam and Slab Raft Foundation
- Cellular Raft Foundation
c. Strip Foundation
d. Trench-Fill Foundation
2. Deep Foundation
a. Pile Foundation
FOUNDATIONS INA105/151
1. Shallow Foundation
Shallow foundation or sometimes called ‘spread footing’ usually refers to those being rested on stratum with adequate bearing capacity and laid less than 3 meters below ground level. Examples included pad or isolated, raft, strip and trench-fill foundations.
The selection of the right type of shallow foundation normally depend on the the magnitude and disposition of the structural loads and the bearing capacity of subsoil. A combination of two or three type of shallow foundation in one single structure is not uncommon
a. Pad Foundation or Isolated Foundation
Pad foundations or isolated foundations are used to support an individual point load such as that due to a structural column. They may be circular,square or rectangular. They usually consists of a block or slab of uniform thickness to spread the load from a column. Pad foundations or isolated foundations are usually shallow. This type of foundation is suitable on high bearing capacity subsoils.
FOUNDATIONS INA105/151
Stages of work in preparing Pad Foundation
Stage 1: Excavation worksStage 2: Formwork preparationStage 3: Reinforcement bar preparationStage 4: Installation of reinforcement and starter barsStage 5: Concreting worksStage 6: Installation of stumps
FOUNDATIONS INA105/151
Stages of work in preparing Pad Foundation
Stage 1: Excavation works
FOUNDATIONS INA105/151
The first stage of works in preparing Pad Foundation is excavation works. Ground will be dug between 1m to 3m deep to make a trench.
FOUNDATIONS INA105/151
Stages of work in preparing Pad Foundation
Stage 2: Formwork preparation
The second stage of works in preparing Pad Foundation is formworks preparation.
Formwork
Reinforcement bar
FOUNDATIONS INA105/151
Stages of work in preparing Pad Foundation
Stage 3: Reinforcement bar preparation
The third stage of works in preparing Pad Foundation is reinforcement bar preparation.
Stages of work in preparing Pad Foundation
Stage 4: Installation of reinforcement and starter bars
FOUNDATIONS INA105/151
The fourth stage of works in preparing Pad Foundation is installing reinforcement and starter bars in formworks.
Starter bar
Reinforcement bar
Stages of work in preparing Pad Foundation
Stage 5: Concreting works
FOUNDATIONS INA105/151
The fifth stage of works in preparing Pad Foundation is concreting works.Concrete Grade M30 is used for this foundation.
Concrete Grade
Concrete mixes (cement, fine aggregate, coarse aggregate) can be expressed as volume grade and ratios:
• Grade M5 (5N/mm²) - 1:5:10 = 1 part of cement, 5 parts of fine aggregate, 10 parts of coarse aggregate.(ordinary concrete)
• Grade M10 (10N/mm²) - 1:3:6 = 1 part of cement, 3 parts of fine aggregate, 6 parts of coarse aggregate.(ordinary concrete)
• Grade M15 (15N/mm²) - 1:2:4 = 1 part of cement, 2 part of fine aggregate, 4 parts of coarse aggregate. (ordinary concrete) - for solid ground floor
• Grade M20 (20N/mm²) - 1:1.5:2 = 1 part of cement, 1.5 parts of fine aggregate, 2 parts of
coarse aggregate. (standard concrete)• Grade M25 (25N/mm²) - 1:1:2 = 1 part of cement, 1 parts of fine aggregate, 2 parts of coarse
aggregate. (standard concrete) • Grade M30 (30N/mm²) - 1:1.5:3 = 1 part of cement, 1.5 parts of fine aggregate, 3 parts of coarse
aggregate. (standard concrete) - for structures and upper floor
• Grade M35 (35N/mm²) - 1:1.6:2.9 = 1 part of cement, 1.9 parts of fine aggregate, 2.9 parts of coarse aggregate. (standard concrete) - for structures
- Cement (Portland cement) - made from limestone and clay and is generally produced by wet process.- Fine Aggregate - those which will pass a standard 5mm sieve . (Sand)- Coarse Aggregate - those are retained on a standard 5mm sieve. (Gravel, crushed stone)
FOUNDATIONS INA105/151
Stages of work in preparing Pad Foundation
FOUNDATIONS INA105/151
CoarseAggregate(gravel)
FineAggregate(sand)
Portland cement
Stages of work in preparing Pad Foundation
Stages of work in preparing Pad Foundation
Stage 6: Installation of stumps
FOUNDATIONS INA105/151
The final stage of works in preparing Pad Foundation is installing stumps.
Stump
FOUNDATIONS INA105/151
Pad Foundation Is Completed
Stages of work in preparing Pad Foundation
Pad Foundation
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Column starter bars
FOUNDATIONS INA105/151
Pad Foundation
FOUNDATIONS INA105/151
Pad Foundation
(Shallow Foundation)
Pad Foundation
Stump
Pad Foundation reinforcement bar
Column starter bars
High bearing capacity subsoil
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Soil
Starter bars
Reinforced concrete stump
Cross Sectional View(Not to scale)
FOUNDATIONS INA105/151
Pad Foundation (Shallow Foundation)
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Reinforced concrete (Grade M30)
Reinforcement bars 12mm diameter
High bearing capacity subsoil
Reinforced concrete stump
1m to 3mdeep
Ground Level
Sand screed 25mm thk.
Floor finishes (tiles)Interior skirting
Soil
Interior part of buildingExterior part of building
Column reinforcement bars
Column
Drain
Plaster
Reinforcement bars 12mm diameter
Skirting
Hardcore
Concrete
Reinforced concrete stump
Concrete (Grade M25) Floor 150mm thk.
Concrete ground Beam (Grade M30)
Cement render
Hardcore 150mm thk.
Pad Foundation & Solid Ground Floor
Cross Sectional View(Not to scale)
FOUNDATIONS INA105/151
Reinforced concrete (Grade M30)
Starter bars
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Apron
High bearing capacity subsoil
Brick wall
Sand blinding 25mm thk.
Damp-proof MembraneGround Level
b. Raft Foundations
The principle of any raft foundation is to spread the load over large area, normally the entire area of the structure. It usually consists of a concrete slab which extends over the entire loaded area. It may be stiffened by ribs or beams and floor incorporated into the foundation .This method often needed on soft or loose soils with low bearing capacity as they can spread the loads over larger area.
Raft foundation has the advantage of reducing differential settlements as the concrete slab resists differential movements between loading positions.
Three types of raft foundation:
1.Solid Slab Raft Foundation Solid slabs are constructed of uniform thickness over the whole raft area. This foundation suitable on soft or loose soils with low bearing capacity as it can spread the loads over larger area.
FOUNDATIONS INA105/151
2. Beam and Slab Raft Foundation
Beam and slab rafts are an alternative to solid slab raft and are used where poor soils encountered. The beams are used to distribute the column loads over the area of the raft , which usually results in a reduction of the slab thickness. The beams can be upstand or downstand depending upon the bearing capacity of the soil near the surface.
3. Cellular Raft Foundation
This foundation can be used where a reasonable bearing capacity subsoil can only befound at depths where beam and slab techniques become uneconomic. The construction is similar to reinforced concrete basements except that internal walls are used to spread the load over raft and divide the void into cells.
FOUNDATIONS INA105/151
1. Solid Slab Raft Foundation
FOUNDATIONS INA105/151
2. Beam and Slab Raft Foundation
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3. Cellular Raft Foundation
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Beam & Slab Raft Foundation & Ground Floor (Shallow Foundation)
FOUNDATIONS INA105/151
Stages of work in preparing Beam & Slab Raft Foundation
Stage 1: Excavation worksStage 2: Installation of FormworksStage 3: Installation of Reinforcement Bars For BeamsStage 4: Installation of Damp Proof Membrane (DPM)Stage 5: Installation of Reinforcement Bars For SlabStage 6: Concreting works
Stages of work in preparing Beam & Slab Raft Foundation
Stage 1: Excavation works
FOUNDATIONS INA105/151
The first stage of works in preparing Beam & Slab Raft Foundation is excavation works. Installing pipes for sewage and plumbing are done at this stage.
FOUNDATIONS INA105/151
Stages of work in preparing Beam & Slab Raft Foundation
Stage 2: Formworks preparation
The second stage of works in preparing Beam & Slab Raft Foundation is formworks installation.At this stage valley are formed for beams and compacting works are done.
FOUNDATIONS INA105/151
Stages of work in preparing Beam & Slab Raft Foundation
Stage 3: Installation of Reinforcement Bars For Beams
The third stage of works in preparing Beam & Slab Raft Foundation is reinforcement bar installation.
Reinforcement bars
FOUNDATIONS INA105/151
Stages of work in preparing Beam & Slab Raft Foundation
Stage 4: Installation of Damp Proof Membrane (DPM)
The fourth stage of works in preparing Beam & Slab Raft Foundation is installation of Damp Proof Membrane(DPM)
DPM sheet
Stages of work in preparing Beam & Slab Raft Foundation
Stage 5: Installation of Reinforcement Bar For Slab and Starter Bar
FOUNDATIONS INA105/151
The fifth stage of works in preparing Beam & Slab Raft Foundation is installation of reinforcement bars for slab and starter bar after installation of DPM
Slab reinforcement bar
Starter bar
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5. Concreting
Stages of work in preparing Beam & Slab Raft Foundation
Stage 6: Concreting works
The sixth stage of works in preparing Beam & Slab Raft Foundation is concreting works. The suitable concrete is Grade M25.
FOUNDATIONS INA105/151
The Raft Foundation
Stages of work in preparing Beam & Slab Raft Foundation
FOUNDATIONS INA105/151
Beam & Slab Raft Foundation
Compacted Hardcore
Beam & Slab Raft Foundation (Grade M25 concrete)
Column starter bars
Low Bearing Capacity Subsoil DPM
Slab Reinforcement bar
Beam Reinforcement bar
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
A
Hardcore 150mm thk.
Column starter bars
Reinforced concrete (Grade M25) foundation forming ground floor slab 150mm thk.
Sand Blinding 25mm thk.
Damp-Proof Membrane(DPM)
Slab Reinforcement bars
Beam Reinforcement bars
Beam & Slab Raft Foundation (Shallow Foundation)
Cross Sectional View (Detail A)(Not to scale)
FOUNDATIONS INA105/151
Formwork
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Low bearing capacity subsoilDownstand beam
Sand screed 25 mm thk
Floor FinishesSkirting
Cement render
Drain
Low bearing capacity subsoil
Interior part of building
Exterior part of building Column reinforcing bars
Column
Concrete slabHardcore
Hardcore 150mm thk
Plaster Reinforced concrete (Grade M25) forming ground floor slab150mm thk.
Sand Blinding 25mm thk
Damp-proof Membrane(DPM)
Slab Reinforcement bars
Beam Reinforcement bars
Beam & Slab Raft Foundation & Solid Ground Floor
Skirting
Cross Sectional View(Not to scale)
FOUNDATIONS INA105/151
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Apron
Downstand beam
Damp-proof Course(DPC)
Column starter bars
Brick wall
c. Strip Foundation
Strip foundation is used to support a line of loads, either due to a load-bearing wall, or if a line of columns need supporting where column positions are so close that individual pad foundations would be inappropriate. This type of foundation is suitable on high bearing capacity subsoil.
FOUNDATIONS INA105/151
Stages of work in preparing Strip Foundation
1.Excavation works2.Reinforcement bar preparation3.Concreting
FOUNDATIONS INA105/151
Strip Foundation
FOUNDATIONS INA105/151
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Strip Foundation (Grade M30 concrete) To support a line of loads, either due to a load-bearing wall
Soil
FOUNDATIONS INA105/151
Strip Foundation (Shallow Foundation) with cavity wall
Cross Sectional View(Not to scale)
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
High bearing capacity subsoil
Reinforced concrete (Grade M30)
Longitudinal reinforcement bars 12mm diameter
Weak concrete filling to base cavity
Damp-proof course (DPC)
Brick Cavity wallInsulation
Ground Level
1m
FOUNDATION INA105/151
Strip Foundation with
Cavity Wall
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Weak Concrete filling
Strip Foundation
Insulation
DPC
Cavity Wall
High bearing capacity subsoil
Drain
Interior skirting
Floor finishes
Interior part of buildingExterior part of building
Plaster
Concrete floor slab 150mmthk
Cement/sand screed 25mm thk
Damp-proof membrane(DPM)
Concrete slab
Hardcore
Strip Foundation with cavity wall and Solid Ground Floor
Skirting
Hardcore 150mm thk
Sand blinding 25mm thk
Cross Sectional View(Not to scale)
FOUNDATIONS INA105/151
Longitudinal reinforcement bars
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Apron
High bearing Capacity subsoil
Weak concrete filling
Reinforced concrete (Grade M30)
Damp-poof course (DPC)
Cement render
Ground Level
InsulationBrick cavity wall
d. Trench-Fill Foundation
Trench -fill foundation is almost similar to strip foundation. Trench-fill foundations can be dug deeper and bigger than strip, which means they are particularly practical where the water table is high, where soil is loose and unstable, and in areas with heavy clay soils. The thickness of any trench -fill foundation should be not less than 500mm and the foundation concrete should finish about 150mm to 100mm below ground level. The trench sides may need to be lined with a slip membrane unless the soil is firm. This type of foundation is suitable on high bearing capacity subsoils.
FOUNDATIONS INA105/151
Stages of work in preparing Trench-Fill Foundation
1.Excavation works2.Reinforcement bar preparation3.Concreting
FOUNDATIONS INA105/151
Trench-Foundation
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Trench-Foundation (Grade M25 concrete) To support a line of loads, either due to a load-bearing wall
Soil
FOUNDATIONS INA105/151
Trench-Fill Foundation (Shallow Foundation)
Cross Sectional View(Not to scale)
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
High bearing Capacity subsoil
Reinforced concrete Grade M30
Longitudinal reinforcement bars 12mm diameter
Weak concrete filling to base cavity
Brick Cavity wall
Insulation
Ground Level
1-2mdeep
Damp proof course (DPC)
Cavity Wall
FOUNDATION INA105/151
Trench-Fill Foundation with
Cavity Wall
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
DPC
Weak Concrete filling
Insulation
Trench-Fill Foundation
High bearing capacity subsoil
2. Deep Foundation
1. Pile Foundation
Pile foundation is a form of foundation using piles to transfer the loads of a structure down to a firm soil stratum with sufficient load-taking capacity. Suitable for multi storey building and on low bearing capacity subsoil.
Materials for piles can be of:
1.Precast concrete2.‘H’ section steel piles3.Metal sheets piles4.Timber or bakau (mangroves) piles5.CISS or Cast-In-Steel-Shell/pipes piles
FOUNDATIONS INA105/151
Precast concrete piles
MATERIALS FOR PILING
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Precast cylindrical concrete piles
1. Pre-Cast Concrete Pile
Pre-cast or pre-stressed concrete piles are one of the most commonly used concrete piles. Pre-cast concrete piles are typically made with steel reinforcing and pre-stressing tendons to obtain the tensile strength required, to survive handling and driving, and to provide sufficient bending resistance. Long piles can be difficult to handle and transport. Pile joints can be used to join two or more short piles to form one long pile. Pile joints can be used with both precast and pre-stressed concrete piles. Pre-cast concrete piles are driven into the ground and used for deep foundations to support structures in residential houses, commercial construction, such as buildings and bridges. They are also used for: heavy highway, public works, marine, and industrial applications.
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Pre-Cast Concrete Pile
MATERIALS FOR PILING
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Pre-Cast Concrete Pile
MATERIALS FOR PILING
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MATERIALS FOR PILING
Steel ‘H’ section piles
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2. H-Pile
H- piles are the ideal solution when foundations are required for complex structures or where the ground conditions are difficult. The properties of steel mean that they can be used to resist tensile as well as compressive loads and they can be designed for bending. They are ideally suited to hard driving through difficult ground conditions eg. silty, fine, water bearing sand containing cobles and boulders/ dense sands and gravels/ glacial till and are particularly effective when founded on rock or a similar hard stratum
MATERIALS FOR PILING
FOUNDATIONS INA105/151
Steel Sheet piles
3. Metal Sheet Pile
A sheet pile wall is a row of interlocking, vertical pile segments installed to form an essentially straight wall with aplan dimension sufficiently large enough for its behavior to allow for the analysis of a .3048-meter (1 foot) widevertical segment of the wall cross-section. Sheet pile walls are typically used as earth retaining structures alongshorelines to allow for higher exposed grades to occur adjacent to lower river bottoms, dredge or mud lines. Sheetpiling can also be used to retain fill around open landside excavations via rectangular trenches or circularcofferdams.
MATERIALS FOR PILING
FOUNDATIONS INA105/151
3. Metal Sheet piles
MATERIALS FOR PILING
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Metal Sheet Pile
Steel Sheet piles
MATERIALS FOR PILING
Bakau piles (mangrove)
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4. Timber Pile
The mangrove piles are widely used in peninsular Malaysia for most building and homes. The use of mangrove piles is also recognized in other countries, Malaysia contractors and developers are so confident that the mangrove piles can actually be used for piling in all buildings and homes due to the mangrove wood nature superb density and its wood’s strength.
The mangrove piles are not only cheap, but it is also easy to handle in most pilling during construction work. The buildings which are using mangrove piles as foundation can at least stand for a decades or more than 10 years. The use of mangrove wood in piling brings so much of benefits and advantages. Cheap, Strong Strength, High Density, Long Lasting
MATERIALS FOR PILING
FOUNDATIONS INA105/151
CISS or Cast-in-Steel-Shell piles Steel pipes pilesSource: http://www.foundationpiledriving.com/ciss.htm 200px-Metal_tubes_stored_in_a_yard[1]
5. CISS or Cast-in-Steel-Shell piles
MATERIALS FOR PILING
TYPES OF PILE CONSTRUCTION
There are two common types of pile construction:
1.Displacement piles
Displacement piles cause the soil to be displaced radially as well as vertically as the pile shaft is driven or jacked into the ground.
2. Non-displacement or replacement piles
Non-displacement, soil is removed and the resulting hole filled with concrete or a precast pile is dropped into the hole and grouted in.
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Pile is driveninto the soil
1. Displacement pile 2. Non-displacement or Replacement pile
Soil is removedby using boring rig and drillto form a hole
Soil
Ground level
or
Precast pile is dropped into the hole
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Bed rock or stratum soil on firm base
Concrete is pored into the steel pipes in the hole to form pile
TYPES OF PILE CONSTRUCTION
LOADING SUPPORT TO PILE
Load from a superstructure is transmitted to the subsoil either by:
1.Skin friction - load is supported by the frictional resistance so created between the contact surface of the pile and the embracing soil.
2.End-bearing - load is support by resting onto a firm stratum such as bed-rock or stratum of subsoil with the required bearing capacity.
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1. Skin friction support
Piles
Loading Support to Pile
Bed rock or stratum soil
on firm base
2. End-bearingsupport
Pile caps
Friction
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Ground level
Soil
Friction
Building
METHODS OF PILING
Piling methods can be done in several way depending on factors mentioned earlier, they are:
1.Driven piling (Displacement)
Piles are driven into the ground using a pile driver. Driven piles are either wood, reinforced concrete, or steel.
a. Gravity hammerb. Diesel hammerc. Hydraulic hammerd. Vibratory pile drivere. Silent pile hammer
f. Air hammer
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2. Drilled piling (Non-displacement)
Piling in which boring is done until the hard rock or soft rock layer is
reached in the case of end bearing piles.
a. Caissonsb. Boring rig and auger drillc. Bucket barrel
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METHODS OF PILING
1. Driven piling (Gravity (Drop) hammer)
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Gravity pile for bakau
The drop hammer consists of a heavy ram in between the leads. The ram is lifted up to a certain height and released to drop on the pile. This type is slow and therefore not in common use. It is used in the cases where only a small number of piles are driven.
METHODS OF PILING
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1. Driven piling (Diesel Hammer)
Diesel hammer piling in action
A modern diesel pile hammer is a very large two-stroke diesel engine. The weight is the piston, and the apparatus which connects to the top of the pile is the cylinder. Piled riving is started by having the weight raised by auxiliary means usually a cable from the crane holding the pile driver — which draws air into the cylinder. The weight is dropped, using a quick-release. The weight of the piston compresses the air, heating it to the ignition point of diesel fuel. Diesel fuel is added/injected into the cylinder. The mixture ignites, transferring the energy of the falling weight to the pile head, and driving the weight back up.
METHODS OF PILING
1. Driven piling (Hydraulic Hammer)
Hydraulic hammer piling in action
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A hydraulic hammer is a modern type of piling hammer used in place of diesel and air hammers for driving steel pipe precast concrete, and timber piles. Hydraulic hammers are more environmentally acceptable than the older, less efficient hammers as they generate less noise and pollutants. However, in many cases the dominant noise is caused by the impact of the hammer on the pile, or the impacts between components of the hammer, so that the resulting noise level can be very similar to diesel hammers.
METHODS OF PILING
Vibratory pile driver in action
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1. Driven piling (Vibratory Pile Driver)
Vibratory pile hammers contain a system of counter-rotating eccentric weights, powered by hydraulic motors, and designed in such a way that horizontal vibrations cancel out, while vertical vibrations are transmitted into the pile. Vibratory hammers can either drive in or extract a pile; extraction is commonly used to recover steel "H" piles used in temporary foundation shoring.
METHODS OF PILING
1. Driven piling (Silent Pile Driver)
Silent pile driver in action
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The Silent Piler is a hydraulic machine for vibration-free installation or extraction of sheet piles. The machine operates by gripping previously driven piles to provide reaction force for pressing in the next pile. The Silent Piler works on top of the reaction piles and self-moves to the next position as illustrated in the adjacent picture. This technique allows pile driving at sites which are not accessible for conventional piling techniques. Only a relatively light-weight service crane is needed to pitch the sheet piles.
METHODS OF PILING
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1. Driven piling (Air Hammer)
Air hammer pile in action
Very basic hammer design, impact based with a rapid blow action and air powered . Less affected by ground type, typically used to finish drive to depth, if not for the full drive. Can be handled by an excavator. Will drive sheets into virtually all ground conditions.
METHODS OF PILING
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2. Drilled piling (Caissons)
Caissons pile driling in progress
A caisson is a retaining structure that is normally water tight that is used to allow construction work to be undertaken under dry conditions below the water table (including below the surface of a river or lake). Examples of when a caisson might be used include on a river bed during the construction of bridge pillars and foundations, or during the construction of a shaft. A pile is a type of deep foundation which usually extends to a significant depth in the ground compared to it's cross sectional area. Piles may be either driven or cast in place.
METHODS OF PILING
2. Drilled piling (Boring Rig and Auger Drill)
Boring rig and auger drilling in progress
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This piling method is ideal for use in cohesive soils. The rotating auger screws into the strata reaming out the soil. Once the required depth has been achieved the steel cage and concrete is placed. These highly mobile rigs are economic to use on large open sites with cohesive ground, and on some chalk or sand, which have good access. Smaller models are suitable for internal use. As a rotary auger causes minimal vibration it is ideal for use next to buildings or underground services
METHODS OF PILING
2. Drilled piling (Bucket Barrel)
Bucket barrel drilling in action
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METHODS OF PILING
Stages of work in preparing Deep Foundation
Stage 1: Piling worksStage 2: Excavation and pile cutting worksStage 3: Preparation and fabrication of reinforcement for pile capStage 4: Preparation of pile cap formworkStage 5: Installation of pile cap reinforcement bar and starter bar Stage 6: Concreting worksStage 7: Installation of stumps
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Stages of work in preparing Deep Foundation
Stage 1: Piling works
Point for piling
The first stage of works in preparing Deep Foundation is piling works that involve 1. Points setting. 2. Piling 3. Piling Jointing (where more piles are required).
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Jointing the pile coupling end plates
Welding the end plates
Stages of work in preparing Deep FoundationStage 1: Piling works
Stages of work in preparing Deep Foundation
Stage 2: Excavation and pile cutting works
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Concrete piles
The second stage of works in preparing Deep Foundation is excavation and pile cutting works. Backhoe loader is needed to excavate the soil and hydraulic pile cutter is required to cut the piles.
Pile cutting in action
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Stages of work in preparing Deep Foundation
Stage 2: Excavation and pile cutting works
Hydraulic pile cutter
Concrete piles
Stages of work in preparing Deep Foundation
Stage 3: Preparation & Fabrication of reinforcement bar for pile cap
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Pile Cap reinforcement bar
The third stage of works in preparing Deep Foundation is preparing and fabricating reinforcement bar for pile cap..
Stages of work in preparing Deep Foundation
Stage 4: Preparation of formworks for pile cap
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Formwork
The fourth stage of works in preparing Deep Foundation is preparing formworks for pile cap
Stages of work in preparing Deep Foundation
Stage 5: Installing pile cap reinforcement & starter bars in formworks
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The fifth stage of works in preparing Deep Foundation is installing pile cap reinforcement & starter bars in formworks.
Pile Cap reinforcement bar
Starter bar
Stages of work in preparing Deep Foundation
Stage 6: Concreting works
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The sixth stage of works in preparing Deep Foundation is concreting. The suitable concrete is Grade M30.
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Pile Caps
Stages of work in preparing Deep Foundation
Stage 6: Concreting works
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Stages of work in preparing Deep Foundation
Stage 7: Installation of stumps
StumpPile Cap Starter bar
The final stage of works in preparing Deep Foundation is installing the stumps.
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Deep /Pile FoundationDeep foundation is completed and ready for ground beams works
Deep FoundationsStarter bar
Pile Foundation
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Piles
Piles Cap
Column starter bar
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Pile Foundation
(Deep Foundation)
Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Low bearing capacity subsoil
Pile CapPile
Stump
Pile Cap reinforcement bar
Column starter bar
Soil
Cross Sectional View(Not to scale)
Pile Foundation (Deep Foundation)
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Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Low bearing capacity subsoil
Piles
Reinforced concrete stump
Reinforced concrete pile cap (Grade M30)
Reinforcement bars 12mm diameter
Pile Cap
1m to 3mdeep
Starter bar
Ground Level
Pile Foundation & Suspended Ground Floor
SkirtingSand screed 25mm
Floor finishes (tiles)
Damp-proof Membrane
Cement render
Drain
Reinforcement bars 12mm diameter
Interior part of building
Hardcore 150mm thk.
Column
Columnreinforcement bars
Sand blinding 25mm
Piles
Floor reinforcement bars 10mm diameter
Reinforced concrete (Grade M25) ground floor slab 150mm thk.
Reinforced concrete stump
Starter bars
Skirting
Concrete Ground Beam (Grade M30)
Ground beam reinforcement bars
Cross Sectional View(Not to scale)
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Note: Graphic symbols illustrated are not to architectural standard symbols. Students are advised to refer to the building construction books for proper symbols available at the library.
Apron
Exterior part of building
Low bearing capacity subsoil
Plaster
ConcreteHardcore
Damp-proof Course
Concrete pile cap (Grade M30 )
Ground Level
References:
1. Ivor H. Seeley (1995):Building Technology. Fifth edition. MacMillan.
2. Roland Ashcroft (1992); ConstructionFor Interior Designers. Second Edition. Longman.
3. Roger Greeno (1998):Advanced Construction Technology.
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THE END
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