CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

Module4-Pile construction
What is Piling in Construction?
Piling is a technique used to drive or bore pile foundations into the ground beneath a
building. This method ensures that loads from the structure are effectively transferred to
the ground, providing essential support. Pile foundations are particularly important in
areas with weak soil that cannot adequately support the structure on its own.
What are Pile Foundations?
Pile foundations are slender, elongated structures composed of steel or reinforced
concrete. They are designed to transfer the load from the structure through weak,
compressible materials to more compact, less compressible, and stiffer soil or rock layers
at greater depths. The deeper these piles are inserted, the stronger and more stable the
base becomes for the construction project.
Pile Foundations
Pile foundations are the part of a structure used to carry and transfer the load of the
structure to the bearing ground located at some depth below ground surface. The main
components of the foundation are the pile cap and the piles. Piles are long and slender
members which transfer the load to deeper soil or rock of high bearing capacity avoiding
shallow soil of low bearing capacity The main types of materials used for piles are Wood,
steel and concrete. Piles made from these materials are driven, drilled or jacked into the
ground and connected to pile caps. Depending upon type of soil, pile material and load
transmitting characteristic piles are classified accordingly.
Classification of piles
Classification of Pile with respect to Load Transmission and Functional Behaviour.
 End bearing piles (point bearing piles)
 Friction piles (cohesion piles )
 Combination of friction and cohesion piles
Classification of Pile with respect to type of material.
Timber
 Concrete
 Steel
 Composite Piles
Classification of Pile with respect to effect on the soil.
 Driven Pile ( Displacement pile)
 Bored Pile ( Non Displacement pile)
Classification of Pile with respect to Shore.

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

 On Shore ( Land Pile)

 Off Shore (Marine Pile)
Marine Piling
Marine piling work differs from land piling work in many respects.
 Distance from land
 Depth of water
 Hydrostatic pressure and buoyancy
 Underwater currents
 Wave and swells
 Tidal variation
 Wind and storm
 Cyclone
 Existing navigation and possibility of diversion etc.
 Marine Piling
Offshore Piling Works:
This kind of piling works are mostly carried out in construction of various marine
structures like jetties, harbours, ports, wharfs and bridges on river/sea that are away from
land.
Marine Piles can be installed by
 Tripod Rig.
 Rotary Rig ( Wirth Rig or Ordinary Crawler Mounted Hydraulic Rig)
Marine Piling
Different methods commonly used for advancing the bore holes.
 End on Piling Gantry ( Temporary movable gantry )
 Self elevated Platform ( Jack-up platform )

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

Fundamental Types of Piling Based on Load Transfer

The two main types of piling are end bearing and friction piles:
End Bearing Piles
End bearing piles transfer loads directly to a deeper stronger soil or rock layer below the
surface.
Friction Piles
Friction piles transfer load by friction between the surrounding soil and the surface of the
pile over its full length.
Various Types of Piling Based on Materials and Construction
Given the importance of pilings and the diverse needs of the locations and facilities where
pilings are used it is no surprise that there are many various different types of pilings.
Let’s take a look at four broad major categories of piling.
Steel Piling
Steel piles are used in a number of construction projects due to their excellent strength
and ability to carry a large amount of weight. Generally speaking, fewer steel piles are
required for a given project compared to piling constructed out of alternative materials
because of the load bearing potential of steel piles. This often provides economic
advantages to the project since fewer total piles are needed, thus reducing materials use

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

and the time and labor involved in driving the piles.

Wood or Timber Piling
Wood piles are another popular and excellent option. This type of piling is traditionally
treated with a coating in order to prevent insects from boring into the structure, thus
increasing durability. Wood or timber pilings have the advantage of being relatively
lightweight to transport compared to steel piling. Wood is also a renewable resource and
thus offers ecological advantages that may appeal to some companies and consumers. The
wood can also be treated to make it suitable for a number of different environments even
if it is going underwater.
Composite Piling
This type of piling is made from different types of materials that are put together to form
a single, more resilient pile. This style is particularly beneficial for marine applications
since it is durable enough to withstand tough aquatic conditions. It is also completely
customizable, and can be specifically designed to fit the needs of the particular project.
Concrete Piling
Concrete is incredibly sturdy, and comes in various different types. Reinforced concrete
has rebar running through the pile in order to increase its strength. Prestressed concrete
piles are great for having a material that is resistant against tension. Concrete piles can be
created and installed at the job site, which is referred to as a “cast in situ” piling. This
avoids the need to transport the piling, often resulting in cost savings. However, concrete
piling can also be created off-site and then pile drived into place to allow for greater
control of the finished product.
Methods of Constructing Piles
It’s important to note that the pile foundation and pile are two different things, yet they
work in conjunction to ensure that piling can support strong loads. A pile foundation is
typically defined as the series of columns that act as the base for structures, whereas the
pile itself is the column or cylinder that aids in transferring the load to the lower subsoil.
Driven Piles
Driven piles are the classic type of pile foundation. They can be constructed with timber,
precast concrete, or steel.
Timber Piles: Used mainly for coastal works, sea defenses, and jetties.
Precast Concrete Piles: Reinforced to withstand driving stresses, they are usually pre-
pressed with a square or octagonal section.
Steel Piles: Available in tubular, box, or H sections. Interlocking steel sheet piles are
widely used for wall construction.
Driven piles increase soil bearing capacity by compacting the soil around the pile as it is

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

driven into the ground.

Bored Piles
Bored piles, also known as replacement piles or drilled piles, are constructed when large
holes are drilled in the ground and filled with concrete. They transfer the load above
ground to the deep rock and soil layers below with minimal settlement.

Rotary Bored Piling: Used when there are significant obstructions in the ground.
Involves installing a temporary casing and removing the arisings before placing a steel
reinforcement cage and filling with concrete.
Continuous Flight Auger (CFA) Piling: A versatile method where concrete is pumped
into a bored hole, then a steel reinforcement cage is inserted.
Driven and Cast-In-Situ Piles
This method combines driven piles and cast-in-situ concrete. A casing is driven into the
ground, and concrete is poured into the casing to form the pile.
Permanent Casing Type: Uses a tubular casing made from reinforced steel, driven into
the ground, and filled with concrete.
Comparative Analysis of Piling Methods

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

Type Advantages Disadvantages

Driven Piles Increases soil bearing capacity, suitable for Noisy, vibration can affect
deep foundations structures

Bored Piles Minimal vibration, effective in obstructions Requires more equipment, ca

Driven and Cast-In- Combines benefits of driven and bored Complex installation process
Situ Piles piles

Aggregate Piles Environmentally friendly, good for soil Limited load capacity, not sui
improvement deep foundations

Precast concrete piles:

➢ Formed in a central casting yard to the specified length, cured and shipped to the
construction sites. or If space is available, casting yard may be provided at the site
➢Length upto 20m and precast hollow pipe piles can go up to 60m
➢ Shorter piles can carry load up to 600kN, and capacity of longer pile can be as large
as 2000KN (in some cases)
Prestressed concrete piles: Formed by tensioning high-strength steel prestress cables
and casting the concrete pile about the cable The prestress cables are cut, when the
concrete hardens Cast in situ pile Formed by making a hole in the ground and filling it
with concrete If the hole is formed by drilling, then it is called bored cast in situ. If it is
formed by driving a metallic shell or a casing into the ground, then it is called driven cast
in situ. If during concreting the casing is left in position, then it is termed as cased pile. If
the casing is gradually withdrawn, then it is termed as uncased pile.
Precast and Prestressed pile: Use in marine structure. Prestressed piles have large
vertical load and bending moment capacity and are used in such installation
Cast in-situ Pile: Soil of poor drainage quality Suited in places where vibrations are
avoided to save the adjoining structures Based on displacement of soil.
Displacement Piles : All driven piles are displacement piles as the soil is displaced
laterally when the piles is installed.
Non-Displacement Piles : Bored piles are non- displacement piles
Advantages of precast concrete pile:

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

•Piles are cast in controlled environment

•The required number of piles can be cast in advance
•Loose granular soil is compacted
•The reinforcements remain in proper position.
Disadvantages of precast concrete pile:
•Addition reinforcements are required due handling and transportation
•Special equipments are required for handling and driving
•Piles can be damaged during handling and transportation
•If the soil is saturated, then pore water pressure is developed which reduces the shear
strength of the soil.
•Length adjustment is difficult
Advantages of cast-in-situ concrete pile:
•The length of the shell or pile can be increased or decreased
•No additional reinforcement is required
•Additional pile can be installed quickly
•Little chance of damage due to handling and transportation
Disadvantages of cast-in-situ concrete pile:
•Proper quality control
•Loose granular soil is not compacted significantly
•A lot of storage space is required for materials
Bored cast-in-situ piles: Large diameter pile can be made. Installation can be made
without appreciable noise or vibration. Boring may be loosen the granular soil. In uncased
pile, concreting is difficult due to the presence of drilling mud. Bored piles are commonly
cheaper. Length of the pile can be changed or varied depending the ground condition.
Driven cast-in-situ piles: Diameter of the pile can not be made too large. More noise and
vibration . Granular soil is compacted . Drilling mud is not required. It is costlier
(especially the cased one). Length adjustment is difficult.
 supported on temporary/ permanent piles.

Pile Load tests on piles are conducted on completion of 28 days after casting of piles.
Two types of tests namely initial and routine tests, for each type of loading viz. vertical,
horizontal (lateral) pull out, are performed on piles.

Pile Load Test Procedure

The following the pile load test procedure as per IS code,

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

pile load test procedure

 The sets up for the load test on a pile consist of two anchor piles provided with an
anchor girder or a reaction girder at their top as shown in Fig.
 The test pile is generally installed between two anchor piles in such a manner in
which the foundation piles are to be installed.
 The test pit should be at least 3B or 2.5 m clear from the anchor piles.
 The toad is applied through a hydraulic jack resting on the reaction girder. The
measurements of the settlement of the pile are recorded with the help of three dial
gauges, with respect to a fixed reference mark.
 The test is conducted after a period of 3 dales after installation of the test pile in
sandy soils, and after a period of one month after the installation of the test pile in
silts and soft days.
 This is because by driving the test pile the soil properties are altered and with the
passage of time much of the original properties are restored.

Initial Load Tests on Piles

This test is performed to confirm the design load calculations and to provide guidelines
for setting up the limits of acceptance for routine tests. It also gives an idea of the
suitability of the piling system. Initial Test on piles are to be carried out at one or more

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

locations depending on the number of piles required. Load applied for the initial (cyclic)
load test is 2.5 times the safe carrying capacity of the pile. Loading for Initial Tests is
conducted as per Appendix ‘A’ Clause 6.3 of IS-2911 Part IV.

Routine Load Tests on Piles

Selection of piles for the Routine Test is done based on number of piles required subject
to maximum of ½% of total number of piles required. The number of tests may be
increased to 2% depending on the nature / type of structure. The test load applied is 1½
times the safe carrying capacity of the pile.
The Maintained load method as described in Clause 6.2 of IS-2911 (Part IV) – 1985 shall
be followed for loading for the Routine Tests.
This test will be performed for the following purposes:
a) To ensure the safe load capacity of piles
b) Detection of any unusual performance contrary to the findings of the Initial Test.
The tests shall be performed at the cut-off level only. A detailed report for the test result
is prepared.

Vertical Load Tests on Piles

This test will be carried out as stipulated in IS-2911 (Part IV) 1995.
Pile Head – The pile head shall be chipped off till sound concrete is met wherever
applicable. The reinforcement shall be cut and head levelled with Plaster of Paris. A
bearing plate with a hole shall be placed on the head for the jack to rest.
Reaction- Kentledge shall be suitably designed to get the desired reaction on the piles.
Anchor piles (if required) shall be placed at a centre to centre distance of 3 times the pile
diameter subject to a minimum distance of 2 M.
Settlement- 2 dial gauges for a single pile and 4 dial gauges for a group of piles with 0.01
mm sensitivity shall be used. They shall be positioned at equal distance around the piles
on datum bars resting on immovable supports at a distance of 3D (min. of 1.5 m) where
D is the diameter of pile or circumscribing circle for non-circular piles.

Application of load- It shall be applied as specified depending on the type of test (routine
/ initial). Each load shall be maintained till the rate of displacement of the pile top is either
0.1 mm in the first 30 minutes or 0.2 mm in the first one hour or 2 hours whichever occurs

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

first. The next increment in the load shall be applied on achieving the aforesaid criterion.
The test load shall be maintained for 24hrs

Causes of Failure of Piles

Following are the most common causes of failure of piles:

1. Absence of statistical data regarding the nature of soil strata through which the
pile is to be driven.
2. The actual load coming on the pile is more than the design load.
3. Bad workmanship in case of cast-in-situ cements concrete piles.
4. Attack by insert etc. on wooden piles.
5. Breakage due to over especially in case of the timber piles.
6. Buckling of piles due to removal of side support, inadequate lateral support, etc.
7. Lateral forces (wind, waves, currents, etc.)
8. Damage due to abrasion resulting from the absence of suitable protective covering.
9. Improper choice of types of piles.
10. Improper choice of the method of driving the pile.
11. Improper classification.
12. Insufficient reinforcement or misplacement in the case of the R. C. C. piles.
13. The pressure of soft strata is just below the tips of piles.
14. Misinterpretation of the results obtained during the pile load test.
15. Wrongful use of pile formula for determining its load-bearing capacity

Methods of installation of Piles

Dropping weight

Diesel Hammer

Vibratory methods

Jacking Method

VIBRATORY METHOD OF PILE DRIVING

Vibratory methods can prove to be very effective in driving piles through non

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

cohesive granular soils.The vibration of the pile excites the soil grains adjacent to the
pile making the soil almost free flowing thus significantly reducing friction along the
pile shaft.The vibration can be produced by electrically (/hydraulically) powered
contra-rotating eccentric masses attached to the pile head usually acting at a frequency
of about Hz. If this frequency is increased to around 100 Hz it can set up a longitudinal
resonance in the pile and penetration rates can approach up to 20 m/min in moderately
dense granular soils

.Disadvantage: The large energy resulting from the vibrations can damage equipment,
noise and vibration propagation can also result in the settlement of nearby buildings

Micropile: Micropile is a friction pile that can be both drilled and grouted and have a
small diameter. The steel elements in a pile are bonded into the bearing rock or soil with
cement grout’s help. These piles can be quickly installed in various kinds of ground with
the use of drilling equipment. The micropile application has significantly extended to
slope protection, ground improvement, and bearing capacity for various superstructures.
Typically, the micropile diameter varies up to 300 mm. It can be cased or uncased,
reinforced cage or single bar of designed diameter inside the micropile depending upon
the type of application and loading conditions. Micropile performs as an excellent
replacement for conventionally drilled shaft piles. Pile drill rigs allow installation in
restricted access and low headroom interiors, allowing facility upgrades with minimal
disruption to normal operations.

Micropile Process

This kind of deep foundation method includes small-diameter piles with diameters less
than 12 inches. For the construction of micro piles, the ground is drilled using a temporary
casing to stabilize the soil. After reaching the predetermined depth, the drill bit is removed,
and the reinforcement and grout are placed inside the hole. Finally, the temporary casing
is removed, and additional grout is injected. In some cases, a permanent steel casing can
be used in combination with the steel reinforcing member to provide additional lateral as
well as axial capacity. The piling process is illustrated below.

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

Advantage of using a Micropile

Micropiles can resist relatively significant axial loads and moderate lateral loads. To
improve their lateral load deficiency, they can be installed at any angle (battered). This
installation causes low disturbance to adjacent structures. However, they are vulnerable
to buckling due to their being slender, and this issue should be considered in the design.
This piling method’s installation equipment is relatively small and can be mobilized in
limited areas and low headroom conditions.

Features and Capabilities of a Micropile

 High load capacity as compared to other available stabilization systems.

 Quicker one-step installations.
 Provides greater densification for ground improvement with greater skin friction
along the micropile depth.
 There is no need for a pre-drill of a hole for micropile installation because drilling
and casing installation are done simultaneously.
 No disturbance to adjacent structures due to the installation of Micropiles.

Lavanya C N Dept of Civil Engineerng, RRIT

CONSRUCTION TECHNOLOGY FOR SUBSTRUCTURE AND SUPERSTRUCTURE

Diaphragm walls: Diaphragm walls are a versatile technique for building retaining walls
that involves excavating a trench, filling it with a slurry, and then pouring concrete to
form a wall:

1. Excavation: A narrow trench is dug into the ground.

2. Slurry filling: The trench is filled with a bentonite slurry to prevent it from
collapsing.
3. Steel cage: A steel cage is lowered into the trench.
4. Concrete pouring: Concrete is poured into the trench to form the wall.
5. Support replacement: For structural walls, the slurry is replaced with concrete
and reinforcement. For non-structural walls, the slurry is left in place or replaced
with plastic or low strength concrete.

Diaphragm walls can be designed to suit different loads and geometries, and can be used
in various soil types and site conditions.

Lavanya C N Dept of Civil Engineerng, RRIT