This manual about how to install PHC pile ,here describe details.

1. PHC Pile Construction Process of Bismayah New city project

2. Bismayah New City - National Housing Program
BNCP is the first and the biggest city development project throughout the history of Iraq.
Bismayah city is located 10km south east of Baghdad on the Iraqi-Kuwaiti Highway, spread on a
total area of 1,830 Hectare area and is planned to accommodate around 600,000 occupants in a
total of 100,000 residential units. Also the infra-network such as electricity, water supply, and
streets will be constructed. As well as the infra-network, the Government of Iraq will develop
the public facilities such as education, religious, welfare, and commercial facilities as well as
infra-structure such as Water and Sewage Treatment plants. Bismayah New City will fill the lives
of 600,000 citizens of Baghdad with happiness and be the most outstanding world class city
beyond Iraq and Middle East as the first project of the National Housing Program which is
constructed by Hanwha Engineering & Construction Co.
Project Overview

3. Figure: General Geological section map
Project Information
Project
Name
Bismayah New city project, Iraq. Contractor Hanwha Engineering & Construction
Owner National Investment Commission, Iraq Team
name
PC Construction team
Piling
work
Type of pile PHC pile Pile
diameter
450mm Effective Pile
length
Model 1:16m
Model 2:15m
Model 3:13m
Construction
Method
Drilling &
Hammer
Design
Load
800KN Hammer Height 700mm

4. Introduction
PHC(Pre tensioned spun high strength concrete pile) is the trend in recent years a new type of precast
pile in the BNCP.PHC pile compared with bored pile, precast square pile and so on, to overcome in the
poor geological conditions areas prone to quality problems of pile defect. PHC pile has a high degree of
factory, good quality, short curing time, rapid construction, strong adaptability of complex engineering
geological conditions, protection of field environment, etc., are widely used in all kinds of buildings and
structures in the foundation engineering, such as Residential Building, industrial factory building, high-
rise buildings, traffic construction, water conservancy construction, harbor engineering and other
fields. This paper introduces the characteristics of PHC pile, manufacturing technology and
construction methods. Combined with project example, analyzes engineering geological conditions,
construction measures, site pile testing result and site pile driving problems and solutions.
.
ADVANTAGES AND DISADVANTAGES OF PHC PILE
Advantages
(1) Single pile bearing capacity is high, the largest diameter of PHC pile for φ1200 allows single pile
bearing capacity can reach 7800 ~ 11700 kN. Bearing capacity of the unit price is cheap, 30 to 40%
cheaper than the same bearing capacity of piles, pile is 20% less than the average PC.
(2) The bending performance is good, the single pile of PHC piles for φ800 allowable bending force can
achieve 2000 kN.m.
(3) The PHC pile quality is stable and reliable. Now pile factory in Hanwha E & C has its own laboratory
in Bismayah new city Project, can undertake all kinds of material quality check and finished product
sampling, to ensure the quality of pile the factory.
(4) Widely used in under 25 floors of high-rise buildings, industrial buildings, traffic construction, the
foundation of the water conservancy construction, harbor engineering, etc.
(5) The construction speed, short time limit. Generally PHC pile can be installed after seven (07) days
complete fabrication. In case of time limitation in order to improve the production of pile production,
can use high pressure steam curing method, after three (03) days can be used in the construction. With
good construction conditions, it would finish about 25 sets of 13m to 16m long φ450mm pile of one
typical driving/pressing machine within 10 hours.

5. Disadvantage
(1) Pipe diameter is small. Due to the large length to diameter ratio is easy broken, specification
provided L/D (pile length/diameter ratio is less than 100). Products currently PHC pile for the largest
diameter is 1200 mm, according to the requirement of the length to diameter ratio, pile length is
limited.
(2) The need to use special construction equipment (pile driver, piling machine and other auxiliary
equipment) and have a good construction personnel experience and skills. In the process of
construction, especially need to pay attention to construction safety problems.
(3) In the process of construction, construction quality problems easily, control can not meet the
design requirements, such as piling hammer sinking pile body damage, static pressure pile, broken pile
displacement and buoyancy, deflection of pile.
(4) In the process of construction noise and vibration problems. In the process of pile driving, the
sound power level can reach 138 db. Construction noise and vibration will affect the neighborhood
residents of life; the construction vibration will affect the neighboring buildings.
(5) Does not apply to some special geological conditions. PHC pile is not applicable to karst
development formation.

6. PHC Pile Manufacturing Process:
Figure: Material Quality control

7. Figure: Fabrications & Installation of Rebar case.
Figure: Formwork installation
Figure: Concrete Mixing & Casting

8. Figure: PC Strand Pre-Stressing & De-molding the case.
Figure: Steam Curing ,Checking & Testing

9. CONSTRUCTION TECHNOLOGY
PHC pile can be installed utilizing a wide range of methods and each method has its own merits over
the others. A variety of methods and special equipment have been used for the installation of piles.
Installation practices include consideration and utilization of appropriate field methods for storing,
handling, and accurately driving each pile to the desired final position within established tolerances.
The designer should be aware that certain equipment and methods for pile installation have been
known to reduce axial and lateral resistance or damage the pile in certain situations. Hanwha E&C is to
use Hydraulic hammer driving method for PHC pile Installation in Bismayah New City Project in Iraq.
Hammer Driving Method
PHC pile hammer driving method as a rapid rise of a pile construction form, suitable for general clayey
soil and backfill soil, river silt and silty soil, powder soil (sand), non-weight collapsible loess and strong
weathered rock (weathered), hard gravel soil, influence and is not influenced by the underground
water level. Relative to the static pressing machine, piling machine has small, very flexible to move,
convenient use and operation mode for the track, on site requirements loose, especially in the initial
construction, site condition is relatively small, complex road conditions engineering. There are a variety
of methods used to raise the weight to guide the pile including diesel hammer, hydraulic hammer,
hydraulic press-in, and vibratory pile drive/excavator, etc. The most common in Vietnam is to use two
hammers for diesel hammer and hydraulic hammer.
Diesel hammers are two-stroke diesel engines. The weight is the piston, and the part connecting to the
pile is the cylinder. Pile driving is started using auxiliary means. The weight is typically raised using a
cable from the crane holding the pile driver drawing 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 injected into the cylinder and the mixture detonates, transferring the energy to the
pile head and driving the weight back up. The cycle is repeated until the fuel runs out or the crew stops
the process.
Hydraulic hammers are used in place of diesel and air hammers for driving steel pipe, precast concrete
(PHC pile), and timber piles. Hydraulic hammers are more environmentally acceptable than older, less
efficient hammers, as they generate less noise and pollutants.

10. PHC Pile Construction Method
In Bismayah New city , Iraq , the biggest housing city in the Middle east, invested and constructed by
Hanwha Engineering and construction. In this project PHC Pile plant factory make 450mm diameter
PHC pile for foundation. This Project all housing foundation and PHC Pile Supervision, Manage &
Controlled by Hanwha E & C Pile & RC Team.
The construction procedure are as follows:
1)According to the design drawings of construction, land development team make trench by excavator
after that make ground leveling for moving of the Hydraulic hammer machine.
Procedure of Surveying:
Hanwha Surveyor team give Coordinate all corner point of each building according to the drawing for
installation Pile Point by Total Station. Another all pile location given by meter. For installation
coordinate need one good surveyor team. Such as
1. one Surveyor who expert to operate total station
2. one surveyor assistant who can understand surveyor signal and hold prism staff on location
of pile.
3. one total station.
4. Some material such as nail, small length of rebar.
-Operate total station for coordinate setting. - Fixing prism staff on corner pile location.
After coordinate installation should give inspection request to resident Engineer to checking
coordinate and location. For this inspection need another one labor to measure distance between two
points of pile with surveyor team.

11. Test Pile Driving Procedure:
Every building divided by four zones like as A Zone, B zone, C zone, D Zone . A Zone has 66 piles, B zone
has 73 Piles, C Zone has 60 piles and D zone has 66 Piles.
Every Building has two hundred sixty five piles including thirteen test piles. Excluding Test pile another
all pile consider as origin pile. All pile has individual pile number. Test pile should be drive be drive
before origin pile. Test pile need drive to understand the soil condition, soil capacity also calculate the
approximately Pile length and Pile quantity according the driving length ( See example below figure).
For housing and social infra test pile number chosen NCEC from Each building .Test pile number for
housing such as A41,A09,A54,BC01,BC93,BC16,BC104,BC031,BC114,BC046,D54,D09,D41 .During test
pile driving should be observed for understand subsoil condition and also prepare pile estimate as
consider as test pile driving length.

12. For housing Test pile number given by following figure:
For social Building have two types of building such as Primary and secondary. In primary School test
pile number are 6,11,17,22,31,40 and secondary School test pile number are 9,17,25,31,41,58.For
social building test pile number shown following drawing:
Building Name
A Zone
A41,A09,A054
B Zone
BC01,BC93,BC16
C Zone
BC104,BC31,BC114,BC046
D Zone
D41,D09,D54
Primary School
6 11 17 22 31 40
Secondary School
9 17 25 31 41 58

13. Dynamic Test Procedure:
After test Pile driving finish than make 2 piles EOD (End of Driving) to checking Pile capacity. Those two pile
number choose resident Engineer from all driven test piles . In this project Minimum allowable Pile Capacity
assumed 1600KN those value decided by NCEC and Hanwha Structural team by consider subsoil geographic
condition. For checking increase of pile capacity need make BOR (Beginning of Restrike) during origin Pile driving
which pile already made EOD. Also BOR must be making after minimum 7 days from EOD date & BOR Capacity
have to be more than EOD capacity. When make dynamic test there should be present Laboratory team,
Resident engineer and Hanwha staff. Also need all arrangement for making dynamic test like as Pile driving
machine, crane operator, three labor, steel plate and pay loader.

14. Pile Driving Procedure:
1. Before pile driving need some check like as
- Pay loader for bring pile near driving machine.
- Ensure stock pile at site where driving pile.
- Should be checked fuel tank, water tank, hammer wire, Pile lifting wire of hydraulic pile driving
machine.
- Also need to check stock of pile cushion (Wood).
2. Before Start pile driving should be check pile location alignment by twist or rope. Its need check for
avoid pile misplaced. Also check pile location with measuring tape as per drawing.
Figure: Check alignment of pile location.
3. For doing Auguring must be fixed center of pile location and make marking on ground Ф400
surround of pile center point as consider of pile diameter.
4. During Auguring should be noticed some factor-
- Before start auguring chisel center axis and pile location center should be keep same axis.
- When start auguring, chisel was getting vibration that time should be care wherein chisel
don’t deviated from pile center.
- There have approval for auguring 4m depth from the ground.

15. - After auguring should be remove soil by excavator.
Figure: During auguring observed one labor.
4. Before lifting of pile should be check following factors
- Should be check Pile surface surround of pile to determined vertical and horizontal crack on pile
surface. If found any horizontal or vertical crack that’s pile shouldn’t use for driving.
Figure: Checking Vertical & horizontal crack on pile surface.
- Should be fastent wire 1.2m to 1.5m inside from the pile top with PHC Pile very tightly.

16. 5. Must be check head cushion(Wood) inside of driving hammar.Cushion use for following objective-
- Deliver uniform hammar effect to across the pile cross section.
- To prevent pile head damage and vertical crack.Also prevent metalic sound during driving.
Pile head cushion should be change after one pile driving finish because when driving pile cushion
getting burned due to many times hammer effect.
Figure: Change pile Cushion(wood)
6. Crane operator should be lifting pile very carefully and slowly from ground otherwise may appear
horizontal crack middle of pile and will be happen any accident. Also labor should stay away from the
lifting area.
Figure: Lifting PHC Pile from ground.
7. After lifting Pile need to put pile on Pile point which already made auger . That time should be keep
pile center and pile point same axis. Also checking alignment when put pile on pile point.

17. 7. Checking vertical line of PHC pile by the vertical theodolite or plumb line(vertical line rope),
according to the technical requirements of PHC pile Installation. Vertical line rope should be keep
parallel to Pile Edge Axis. Should be checking vertical from two directions. Pile driving, in about 20
meters from the pile machine, each one a 90 - degree direction set theodolite calibration or install
vertical line rope. Before start driving and after five meter driving need to check vertical of pile by
spirit level.
8. During Pile driving one skill experience engineer about PHC Pile stand by there to observe pile
condition and driving procedure. During Pile driving when pile become vibration that time can
understand this pile have vertical problem and also can understand hammer and pile don’t have same
axis.

18. 9. After 10m driving all pile checking pile settlement value .when found desire settlement value that
time make Set value paper. During making set value paper ram height should be keep 700mm.After
Making Set value paper every pile needs to stop driving.
Hanwha structural Team and NCEC make following set value Criteria for Bismayah New city Project
Housing Final Set value criteria are as follows-
SL
No
Pile Length(L) Final Set Value (S) Dynamic Load Test Need
1 L ≤ 10m S ≤ 4mm Yes
2 10m < L ≤ 12m S ≤ 4mm No
3 10m < L ≤ 12m S > 4mm Yes
4 12m < L ≤ DL S ≤ 6mm No
5
L=Design Length
S ≤ 10m No
6 S >10mm Yes
- D.L= Design Length →Model 1:16m, Model 2:15m, Model 3: 13m.
- The pile length in progress will be determined according to the set value of each pile.

19. 11. After Set value made checking desire set value and fill up pile parameter on Set Value paper.

20. Total Hammer driving procedure shown by following Picture:

22. Site Pile driving problems and countermeasures
Pile top broken
During pile driving, pile top appear concrete is broken, and even the head of all structural steel
exposed, as shown in figure.
Cause analysis for Pile top Broken: The quality of pile body appearance does not conform to the
requirements, such as the pile head is uneven, the pile top protective layer is too thin, etc. Pile top and
pile follower contact surface uneven, pile cushion too thin and uneven, pile sinking soil pile is not
vertical, cause the pile top broken by stress concentration.
Quality control measures: Check before pile to improve the quality of pile body, pile should not be
used to do not conform to the requirements of the specification. Check the contact surface of the pile
and follower, such as uneven should be processed before the construction. Stabilizing pile vertical,
piling pile top should add pile cushion, if pile cushion lost effect need to be replaced in a timely
manner.

23. Pile body broken
Pile in the construction of large bending, under repeated hammer, when the pile body can't bear
bending strength, and fracture as shown in figure .
Figure-Pile Body broken
Cause analysis for Pile body broken: When construction, have relatively hard layer. After the pile
driven into encountered chunk hard obstacles. When two or more segment piling, pile on the phase of
the two segments are not the same axis, resulting in a tortuous. Hammer cushion not flat, after a long
fight, pile body under tensile and compressive stress, when the compressive stress value is greater
than the pile concrete compressive strength, the pile body somewhere on generating transverse
cracks, scattered on the surface of concrete, such as high voltage stress, concrete crushing, pile body is
broken. In the process of stacking, lifting, transportation improper also all can appear pile body
damage.
Quality control measures:
Before construction, geological data to see, which is identified on the drawing pile will meet obstacles,
so that the research process with the relevant units. To approach the pile inspection, found that the
pile has a crack (more than) shall not be used, pile tip shall burn on the pile axis. In the process of pile
driving in the early, such as found it vertically in a timely manner to correct, if possible, should pull the
pile, cleaned up the obstacles or backfill soil and pile again. When the pile soil into certain depth
produces serious tilt, it is unfavorable use mobile to correction. Pile extension, to ensure that the
upper and lower two piles in the same axis, better to joint welding with welding. In the process of
stacking, lifting, transportation, according to rules on the operation, found that the pile body cracking
in excess of the prescribed shall not be used.

24. Inclined pile
Pile in the process of construction, pile vertical deviation is too big (rules: vertical deviation pile length
shall not exceed 0.5%) form inclined pile.
Figure: checking inclined pile
Cause analysis for inclined pile: Using hammer type pile, the pile is not vertical, pile cap, pile hammer,
and not in a straight line. The pile when large rigid obstacles, such as the old foundation, the ancient
stone river barge, stone, etc., shall be crowded to one side, the pile deflection. Pile layout too much
too close, produced in the compaction effect of pile driving, the original has been into the pile up or
oblique. When the pile extension, connect the two pile is not in the same axis, the twists and turns.
The excavation method is undeserved, one-off excavation depth is too deep, make the pile side soil
under great pressure, the bending deformation of pile, pile top offset.
Quality control measures for inclined pile: Careful analysis of the geological survey report, if meet
hard obstructions should be cut these obstructions in advance way or use the drill will be obstacles to
wear, and after that can pile driving. For good control of verticality of pile, the emphasis should be on
the first segment pile, pile hammer, pile cap or send rod and pile body the same central axis. Pile when
insert the verticality deviation of pile length shall not exceed 0.5%. Pile driving, in about 20 meters
from the pile machine, each one a 90 - degree direction set theodolite calibration. Was found during
the construction of the pile is not vertical immediately correct. When necessary, pull the pile, and then
piling again. Single pile joint cannot be more than four segments. When the pile extension steel end
plate welding method is used: Section pile up and down to alignment, and on the same central axis,
the period of pile up and down the centerline deviation is not greater than 5 mm.

25. Reduce level (Cut Level) installation:
There every building has individual reduce level, in this project it’s called as cut level.
This level should be writing on every pile in each building. This reduce level (cut Level) taken from
certain bench mark which before given by our survey team at this place. Cut level need to give for find
out actual driving length. For giving cut level need one survey team, Such as
- One surveyor who know operate level machine.
- One surveyor assistant.
Deviation and Cut Level Inspection:
During driving, if hammer axis and pile center are not same axis this time pile become vertically
inclined. For inclined pile Hanwha E & C structural team make following deviation criteria for Bismayah
New City Project which is approved by NCEC.
Verticality(V) Description
V≤1/75 Don’t Need Supplementary
1/75< V ≤1/40 Supplementary(Ref. 03)
V > 1/40 Adding Pile
Figure: Deviation Criteria.
During inspection should be followed above Deviation criteria. Notice that Deviation & cut level should
be check same time.
Figure: Checking Deviation.
For Deviations should be fixing following specification:

26. Figure: Reinforcement details for deviation(Inclined Pile)
After checking deviation, cut level and all set value paper NCEC Resident Engineer give permission for PHC Pile
head cut. Pile head should be cutting along given the cut level on pile. During cutting should be cut all thickness
of pile.
Figure: Pile cutting by Granting Machine.
Remove all pile head with pile remover crasher. When remove the pile head should be take care in
order to avoid head damage ,vertical crack of pile.

27. Inspection of after pile head cut and treatment for problem pile:
Crack, head damage & head broken Check:
Vertical crack can appear on PHC pile head for different reason. If vertical crack thickness crossed from
outside to inside of PHC pile thickness, this one take as a vertical crack and if vertical crack length
would more than 1.5 m after that should be put additional pile for like this this vertical crack but less
than 1.5 m there have technical supplementary.
During careless head remove pile rebar strand become appear from concrete, its called as pile head
damage. For vertical crack & head damage should be apply same supplementary.
Figure: Reinforcement details for crack & head damage.

28. When remove pile head by pile remover crasher during this time pile head became broken due to
improper pile head cutting, stroke with another pile during lifting. For this problem there has following
supplementary-
Figure: Reinforcement details for pile head broken.

29. Water level Check & Treatment:
During driving downside of pile became horizontal crack due to vertical gradient of pile, subsoil
obstruction. For this reason ground water inflow through crack into the pile inside. If ground water
inflow inside of pile, It may be loose his load bearing capacity. So for ensure pile quality need to check
water level of inside pile. Than need to section and make treatment for ground water. Notice that
water level should be check with Resident engineer.
For treatment of pile inside water should be follow below specification:
Division Case 1 Case 2(Low water) Case 3(High water)
Water
Level(WL)
40cm≥WL 40cm<WL<1/3(L) 1/3(L)<WL
Diagram
Treatment
Step 1 No Pumping Pumping or Dewatering Pumping or Dewatering
Step 2 Integrity test will be performed
on 10% of piles in case 2
Integrity test will be perform
on 100% of pile in case 3
Step 3 Integrity test Result
-Pass: Concrete (will be casted
up to half level of pile. And the
rest of pile in case 2 will be
treated the same way.
-Fail: The rest of pile in case 2
will be tested and treated
based on integrity test result.
1)Pass: casting concrete up to
half level of pile.
2)Fail: Addition Pile(This
guideline is limited to one
building where integrity has
been done)
Integrity test Result
Pass: Concrete will be casted
up to full level of pile.
Fail: additional pile will be
Drive which pile integrity
fail.

30. In the process of treatment of water,
For case 1 no need to do anything.
For case 2 need to pumping first all low ground water from inside of pile. After that filled concrete
(30MPa) up to half level a pile from pile bottom with compaction.
For Case 3 need all high water pile pumping first than fill concrete (30MPa) full length a pile from the
bottom of pile. Before concrete casting should be check after pumping water level of pile inside with
Resident Engineer.
Figure: Integrity test for water pile , Bending.
Figure: Pile inside casting for water

31. Bending
In the construction of pile driving, the middle of pile appears large bending under the repeated
hammer, when pile body can’t bear axial bending stress. During driving when pile bottom arrived to
relatively hard layer, non-stabilized soil in this situation pile bottom not go through original center axis.
For this reason appear horizontal crack , bending in middle of pile under the ground. For identify
bending need to use mirror for making sun reflector inside of pile.
Visual Checking System:
Bending Criteria:
-If bend more than 50% of pile inside circle, should be make integrity test.
-If bend less than 50% of pile inside circle, No need do anything.

32. Treatment for bending Pile:
For bending there follows below figure specification:

33. Rebar Install and Check:
After finish all treatment of pile should be fixing connection rebar for bonding pile & foundation. Also
need to provide rebar for deviation, Crack & head damage. For connection reinforcement shown in
below figure:
Figure: Connection Reinforcement details.

34. Pile location tolerance (Base line) check:
- The misplaced of the pile location on the plan after driving shall not be greater than 75mm.
- When the driven pile is deviated toward outside of a foundation (pad, strip, mat foundation etc.)
and the deviation is between 75mm and 150mm, the foundation shall be expanded as much as the
distance measured from the center of the pile and also additional 50% of rebar shall be installed as
referring to Figure 1. If the deviation is toward inside of the foundation, only additional 50% of rebar
shall be added to the foundation.
- When the deviation is greater than 150mm, the supplementary method shall be determined through
the structural analysis.
Figure. Example of additional rebar fixing for misplaced pile.
Additional
50% Rebars
FoundationExpansionRange
Foundation Expansion Range
FoundationExpansionRange

35. Total inspection procedure shown by following diagram:
Inspection Procedure
Surveying
Coordinate & Pile
Location Check
Pile Inspection
Deviation & Cut
Level
Water ,Crack &
Bending
Integrity Test
Additonal Pile
Driving
Water level check
after Pumping
Pile inside concrete level
check after casting
Rebar check for
Crack & Deviation
Foundation
Coordinate & Base
Line Check
Deviation & Cut
check of Add. Pile
water,Crack & Bending
Check of add. Pile