METHOD STATEMENT FOR TEST PILLING WORK (PREBORING PHC PILE)

Comment Response Sheet (CRS)
Project Title

Van Phong 1 BOT Thermal Power Plant Project

Document Title

METHOD STATEMENT FOR TEST PILLING WORK
(Pre-boring PHC Pile)

Document No

Document Type

For Approval

Returned Status

AC

Prepared by

CRS Issued Date

01 Apr 2020

Engineer

YJ Lee

VP1-0-L4-C-GEN-10017

VP1-0-L4-C-GEN-10017-B-CRS

CRS No

No.

Section/
Page

Owner’s Comment

Response to Comment

Review
Date

Status O/C *

Remarks

Page 1 of 15


Comment Response Sheet (CRS)
1

Cover

03/03/2020
(1) Clarification of design calculation for pile class A, B

& C (JIS A5373) to be provided.
27 Mar 2020:
(1)Please add reference of approved calculation for
required weld thickness AND test pile calculation.

03/03/2020
(2) Quality control of cement grouting- tech
specification and welding procedure has to be properly
shown including MS.

27 Mar 2020:
(2) Provide density cement slurry to check at site prior
to fill in the borehole.
Provide estimated volume slurry for each pile and
monitor the loss volume if happen.

20/03/2020
(1) Design calculation for pile (Calculation for
preliminary test pile VP1-0-L4-C-GEN-00020 was
submitted and will be clarified separately.

03/03/2020

O

01/04/2020

O

03/03/2020

O

01/04/2020

O

20/04/2020
(1) Test pile calculation VP1-0-L4-C-GEN-00020 is
add in this MS as an attachment.

20/03/2020
(2) Quality control of cement grouting- tech
specification is updated in MS (item 10.1 Material and
11.4 Cement Milk Grouting) and welding procedure is
updated in MS item 11.6 Pile connection)

Closed

20/04/2020
(2) Base on the technical specification of test piling
work at item 2.2 Pile construction method, 2.2.1 Preboring with root hardening cement slurry (pile fixed
slurry)
Cement

600 kg

Water

420 L

Compressive Strength

200 kg/cm2

Density cement slurry is 1.66.
Tolerance : 1.66 +-5% (From 1.58 to 1.74)
Volume slurry for pile D600 – 20m:
Cement (Ton)

Water (lit)

Cement milk (m3)

2.4

1.7

2.47

Volume slurry for pile D800 – 20m:
Cement (Ton)

Water (lit)

Cement milk (m3)

3.33
2.33
3.4

Monitor the volume on the mixing machine electric
board.
Page 2 of 15


Comment Response Sheet (CRS)
03/03/2020
(3) Clarification for welding work measuring method
(a) Welding quality of work

20/03/2020
(3) DHI have clearance on article 11.6 Pile connection
of this MS Rev.B

27 Mar 2020:
(3a) No WPS was shown.
Welding rode is missing information

20/04/2020
a) WPS was attached in this MS at item 11.6.4
Welding rob will be added in the MS at Item 11.6.4.
Welding quality to be controlled by Visual inspection,
NDT MT test for welding shall be done In accordance
with Welding inspection report of ITP

03/03/2020
(b) Checking/ application of anti corrosion for welding
joints.

20/03/2020

b) Pile Welding joint shall be cover by Slurry Cement

03/03/2020

O

01/04/2020

O

closed

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

O

27 Mar 2020:
(3b) Noted

03/03/2020
(c) Duration of welding joint temperature cooling time
prior to pile driving.

20/03/2020
c) In order to prevent cracking of welding area,
temperature cooling time will be min 1minute.

27 Mar 2020:
(3c) Kindly noted that much different temperature in
very short time have no much effect to avoid.
Reply is not accepted.

20/04/2020
3c) In order to prevent cracking of welding area,
temperature cooling time will be min 10minute.

03/03/2020
(d) Estimation of pile length to be incorporate with pile
bottom layer soil data & EPC visual inspection records.

20/03/2020
(d) Noted, the length of the pile is determined by the
boring log and pile bottom layer soil data.

27 Mar 2020:
(3d) Kindly requested to check the borehole depth,
diameter /soil condition before installing the pile in.
Please describe more information checking bored hole

after drilling.

20/04/2020
(3d) To check the borehole depth, diameter/soil
condition before installing the pile as below:
The length of drilling rod longer than the bore hole.
Checking by mark a red line on the Drilling rod when
get the design depth and using hydrometer to check.

Noted

03/03/2020

O

01/04/2020

O

Page 3 of 15


Comment Response Sheet (CRS)
2

3

Cover

Page 2

03/03/2020
Location of testing pile is not yet stated. And location
should be chosen in consideration with the use of piles
for foundations for example Chimney FDN., Coal
conveyor FDN, and others. Because soil condition is
different from locations.
01/04/2020
Closed
03/03/2020
- The purpose of Test Pile should be stated.
- Number and location of test pile should be stated
- Kind of test must be stated.
01/04/2020
Closed

4

Page 3

03/03/2020
Calender date should be written.

20/03/2020
PRELIMINARY TEST PILE PLAN PLOT PLAN_ VP10-L4-C-GEN-00021 was submitted and it is attached in
this document as Attachment #1 for reference

20/03/2020
The purpose of Test Pile is added in MS.
- Number and location of test pile : please refer to

Attachment #1 VP1-0-L4-C-GEN00021_PRELIMINARY TEST PILE PLAN
- Kind of test : refer to item 1 Purpose of Test Pile
20/03/2020
Calendar date is applied on the top of Schedule.

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

01/04/2020
Closed
5

Page 4

03/03/2020

Capacity of equipment must be stated.
Mobilization of testing equipment should be stated.
01/04/2020
Closed

20/03/2020
Capacity of equipment is added in page 5 in MS (item
8 Mobilize plan of construction heavy equipment).
Mobilization of testing equipment in page 5 in MS
(item 9 Mobilize plan of construction heavy
equipment).
20/03/2020

6

7

Page 4

Page 5

03/03/2020
How much strength is Cement grout ?
01/04/2020
Closed
03/03/2020
Raw material?
Not agree, please share the propose mix design if it will
effect to the pile bearing calculation.

The compress strength of Cement Milk is 20Mpa

20/03/2020
Raw material will be submitted separate with MS
The propose mix design will be submitted separate
with MS

01/04/2020
Closed

Page 4 of 15


Comment Response Sheet (CRS)
8

Page 5

03/03/2020
Material Information said D900? please double check
01/04/2020
Closed

9

Page 5

03/03/2020
Effective prestress should be stated.
01/04/2020

Closed

20/03/2020
Material Information only have 2 kind of Pile (D600
and D800)

20/03/2020
Effective prestress is stated on page 9 (item 10.2 PHC
Pile in MS).

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

20/03/2020
10

Page 5

03/03/2020
250? Please check

It is 300

01/04/2020
Closed
11

12

Page 5

Page 5

03/03/2020
Concrete ?
01/04/2020
Closed

03/03/2020
How the slime at the bottom of borehole is treated after
completion of drilling ?

20/03/2020
It is Concrete and corrected

20/03/2020
The slime at the bottom of borehole will be thrown out
of hole by the air compressor after completion of
drilling

01/04/2020
Closed
20/03/2020
13

Page 5

03/03/2020
How much diameter is borehole ?

The diameter of borehole will be 10cm larger than Pile.

01/04/2020
Closed

14

Page 5

03/03/2020
This sentence is not clear.
- How much is bearing capacity of pile? please clarify.
- Please describe how to use this hammer?

20/03/2020
- The capacity of PHC pile is 6281kN
- A pile is fixed to bearing layers by the drop hammer.

01/04/2020
Closed

Page 5 of 15


Comment Response Sheet (CRS)
15

Page 5

03/03/2020
Please provide:
(i) Pile design calculation report;
(ii) Design drawing of PHC Pile; welding joint;
(iii) Design length, design load of test piles?
(iv) Test piles location drawing?

01/04/2020
Closed

16

Page 6

03/03/2020
Auger should be in the slurry during injection of grout ?
01/04/2020
Closed

17

18

Page 6

Page 6

03/03/2020
Borehole should be kept as vertical during drilling.
01/04/2020
Closed
03/03/2020
Please explain this step, why need to fill the cement milk after
insert PHC pile?

20/03/2020
Attachment documentation:
(i) Design calculation for pile (Calculation for preliminary test
pile VP1-0-L4-C-GEN-00020 was submitted and will be

clarified separately
(ii) Design drawing of PHC Pile; Attachment #2 Drawing of
PHC-D800 and PHC-D600
(iii) & (iv) VP1-0-L4-C-GEN-00021_PRELIMINARY TEST
PILE PLAN was submitted and it is attached in this document
as Attachment #1 for reference
20/03/2020
Auger will not be in the slurry during injection of grout
20/03/2020
Borehole will be kept as vertical during drilling by total station
or plum line.

20/03/2020
Need to fill the cement milk after insert PHC pile if the
Cement Slurry deposit after insert pile.

01/04/2020
Closed

19

Page 7

03/03/2020
The hardening time should be decided by trial mix of cement.
01/04/2020
Closed

20

Page 7

03/03/2020
Please explain:
(i) How to collect water and cement grout during install the
pile?
(ii) How to control quality of cement grout to avoid mixing with
ground water inside the bore hole?
(iii) How to fix top of pile after finish installation? How to check
vertical tolerance of pile is acceptable?

01/04/2020
Closed

20/03/2020
The hardening time cement According to mechanical target of
Cement PCB40 of Nghi Son using at site

20/03/2020
Please explain:
(i) In order to collect water and cement grout during install
the pile shall be create a bend hole near the pile to collect
Cement Slurry and move to other place.
(ii) When Cement Milk over flow on the ground, Ground water
inside the borehole will be pushed out with gravitation of
Cement Milk due to gravitation of Cement Milk heavier than
ground water.
(iii) Using light blow driving pile head until fix to the ground
and then using two direct which have been located at the
near distance to check vertical of pile head.

Vertical tolerance of pile will be applied in TCVN 10667 at
page 18 item 9.2.8 indicated the vertical tolerance is 1% of
pile length are accepted.

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

Page 6 of 15


Comment Response Sheet (CRS)
21

Page 8

03/03/2020
Please supplement:
- WPS for welding joint.
- Welder certificate.
- Temperature of the joint before second and third layer
/ or standby time between 2 layer
- NDT test for the joint is necessary

20/03/2020
Document supplement:
- Welding work and inspection shall be in accordance
with the Welding inspection report on ITP for this test
piling work.
- Each layer welding work shall be done continuously
without standby and cooling time.
- NDT- MT test 5% for the joint will be applied to ITP.

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

O

03/03/2020

O

01/04/2020

C

01/04/2020
Closed
22

Page 8

03/03/2020
How to hold and fix this bottom pile while welding the
upper one?

20/03/2020
The bottom pile will be fixed by wood and checked by
level when welding joint with the upper pile.

01/04/2020
Closed
23

Page 8

03/03/2020
Light blow is how much? Is it equal how many tons?
How weight of the ram?
01/04/2020
Closed

24

Page 9

03/03/2020
Please clarify why we use casing in the installing pile.

20/03/2020
The Light blow will be used to fix the pile get the
required elevation with the weight from 2.5T – 3.7T.
Light blows is around 10 blows/time for this test piling
work. The standard of Light blow(hammering height,
rebound) for mass piling work shall be decided by this
test piling work.
20/03/2020
Just using casing in case the soil was been collapsed
20/04/2020
The casing is applied for proper depth to prevent the
collapsing of the soft and loose soil/sand layer of the
hole.

25

Page 9

03/03/2020
Before setting of counterweight, the area of loading
should be well compacted to avoid overload on the
ground surface or incident during test.

20/03/2020
Noted

01/04/2020
Closed

Page 7 of 15

Comment Response Sheet (CRS)
26

27

28

29

30

Page 12

Page 12

Page 12

Page 13

Page 13

03/03/2020
Add more content on testing report:
1. Pile contractor, boring log near the test pile.
2. Pile installing equipment.
3. Test pile size, length, effective prestress etc.
4. Recommend the ultimate load.

03/03/2020
Calibration of testing equipment shall be submitted as
well
01/04/2020
Closed
03/03/2020
- English please
- Not clear, can not read
01/04/2020
Closed
03/03/2020
Please provide:
- Load value
- Minimum duration for maintain the load value
01/04/2020
Closed
03/03/2020
Lack of 1st cycle application of loads equal to 25, 50,
75, 100% of the pile design load.

20/03/2020
03/03/2020

O

01/04/2020

O

Noted and modified

20/04/2020
In accordance with form of Laboratory the content on
testing report always fully this information. Refer to
VP1-MS for Pre-boring PHC pile Rev B update
03/03/2020

O

20/03/2020
Calibration of testing equipment shall be submitted as
well

01/04/2020

C

20/03/2020
No important in this method, it will be stated in test
result.

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

20/03/2020
- Load value is 200%.
- Duration for maintain of each load value: From 1
hours to 2 hours.

20/03/2020
Additional 1st cycle application.

01/04/2020
Closed

Page 8 of 15


Comment Response Sheet (CRS)
31

Page 13

03/03/2020
According to TCVN 9393-2012: it is recommended
testing load should be equal 250-300% design working
load.

20/03/2020

01/04/2020
Closed

VP1 PJT.

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

According to the contract “Part III-2 Exibit B1 tech
spec section 4.1”, ASTM is also usable standard for

In particular, the ASTM related to the test pile is widely
used internationally therefore there is no problem in
application.
Furthermore, the applied design capacity of the pile is
lower than the allowable pile bearing capacity by
calculation, so a sufficient result can be obtained with

32

Page 13

03/03/2020
How much compressive force is 200% of ?
01/04/2020
Closed

a 200% test load recommended by ASTM.
20/03/2020

The allowable compressive pile bearing capacities are
as following and the capacities are based on the
calculation report.
PHC

D600

Allowable pile

Applied

bearing capacity

design

by calculation

capacity

1,570kN(BHO-08)

1,550kN

Test load
(200%)
3,100kN

2,152kN(BH-45)

33

Page 13

03/03/2020
- For pile head displacements of less than 10 mm, each
load increment shall be maintained until the rate of
settlement is reducing and is ≤0.1 mm/hour
- For pile head displacements of greater than 10 mm,
each load increment shall be maintained until the rate of
settlement is reducing and is ≤0.2 mm/hour.

D800
3,728kN(BH-31)
3,300kN
6,600kN
20/03/2020
- For pile head displacements of less than 10 mm,
each load increment shall be maintained until the rate
of settlement is reducing and is ≤0.1mm/hour
- For pile head displacements of greater than 10 mm,
each load increment shall be maintained until the rate
of settlement is reducing and is ≤0.2 mm/hour.

01/04/2020
Closed

Page 9 of 15


Comment Response Sheet (CRS)

34

Page 13

03/03/2020
Supplement allowance settlement of each load value.

20/03/2020
Allowance settlement of each load value is over 15%
D

01/04/2020
Closed
35

37

Page 13

Page 17

03/03/2020
Supplement the Test Result.
01/04/2020
Closed
03/03/2020
Please provide
- Load value
- Duration for maintain of each load value

20/03/2020
Submit Test Result

20/03/2020
- Load value is 200%.
- Duration for maintain of each load value: From 1
hours to 2 hours.

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

01/04/2020
Closed

Page 10 of 15


Comment Response Sheet (CRS)
38

Page 17

03/03/2020
How much tensile force is 200% of ? And is this
tensile force related with total prestress of pile ?
From the safety factor of calculated capacity, Tensile
capacity is 3.0 and compressive one is 2.5. Is the same
200% of maximum test load between Compression and
Tension ?

20/03/2020
According to the contract “Part III-2 Exibit B1 tech
spec section 4.1”, ASTM is also usable standard for
VP1 PJT.
In particular, the ASTM related to the test pile is widely
used internationally therefore there is no problem in
application.
Technically, the relationship between the safety factor
of the pile bearing capacity and the test load is

different, so there is no problem in testing by applying
a 200% load according to ASTM.

01/04/2020
As for bearing capacity of pile, allowable bearing
capacity has safety factor 2.5 for Compression and
3.0 for Tension to Ultimate. Why the safety factor is
different is Ultimate tensile capacity has more unknown
factors than Ultimate Compressive capacity.
Therefore, 200% x 3.0/2.5 = 240% is recommended,
otherwise ASTM specify 200% for Tension test.
Considering chimney foundation, tensile force of pile
may be important and critical.

20/04/2020

03/03/2020

O

01/04/2020

Closed
O

The tensile pile capacity was selected smaller capacity
between the pile bearing capacity considering the soil
condition and the structural capacity of the pile as
below.
Tensile pile capacity of PHC D600 (Open Coal

Storage yard) from calculation for preliminary test
pile(VP1-0-L4-C-GEN-00020)
TCXD

TCVN

Struct
ural
capaci
ty

958kN

1,673kN

622kN

Min,
Capacit
y
(TCXD,
TCVN,
Structur
al)
622kN

Selecte
d
design
capacit

y

Test
load

500kN

1,000kN

Since the tensile capacity is decided by structural
capacity of pile, the pile may be broken when loading
is applied more than 200% mentioned ASTM D3689.
It is reasonable to apply a test load of 200% according
to the ASTM standards mentioned in the contract.

Page 11 of 15


Comment Response Sheet (CRS)
39

Page 18

03/03/2020
Supplement the Test Result.

20/03/2020
Additional Test Result
20/04/2020
In accordance with ASTM D3689, the test result shall

be supplied for each Compression test, Lateral and
tensile load test after each testing finish.
20/03/2020

40

Page 20

03/03/2020
For prevention of collapse of pile by concentrated force,
inside of pile should be filled with concrete at the top of
pile.

03/03/2020

O

01/04/2020

Closed
O

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

This method will be carried out before test.

01/04/2020
Closed
41

Page 21

03/03/2020
How much horizontal force is 200% of ?

01/04/2020
Closed

42

Page 22

03/03/2020
Supplement the Test Result.

20/03/2020
The allowable lateral pile bearing capacities are as
following and the capacities are based on the
calculation report.
PHC
Allowable pile
Applied
Test load
bearing capacity
design
(200%)
by calculation
capacity
D600
227kN
220kN
440kN
(BHO-08, BH-45)
D800
409kN (BH-31)
400kN
800kN
20/03/2020

Additional Test result

01/04/2020
Closed

Page 12 of 15


Comment Response Sheet (CRS)
43

Page 22

03/03/2020
- Recommend to do the PDA test before static load test
if it is design on one pile.
- The axial bearing capacity result of high strain
dynamic test should be compared with the result of
static load test to confirm the pile length.

20/03/2020
03/03/2020

O

01/04/2020

Closed
O

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

Closed
O

The PDA test only test when Static load test was failed
in order to compare with the result of static load test.
20/04/2020
The PDA test will carried out after get the test result of
Static load test in order to compare with the result of

static load test to confirm the pile length.
The PDA test could not test before the static load test
because the pile head might be broken when testing
PDA by hammer.

44

Page 23

03/03/2020
How much is the desired ultimate capacity?

20/03/2020
The desired ultimate capacity base on wave & stress
measured at the pile tip using the CASE method and
CAPWAP Software.

01/04/2020
Closed
45

Page 23

03/03/2020
Supplement the Test Principle before Test Procedure.
01/04/2020
Closed

46

Page 24

03/03/2020
Please describe ground condition where is crane
placement
01/04/2020
46. OPEN. This information shall be reflected in this
document for site implementation and provide the clues
for review. it should be detail when steel plates shall be
provided and how many steel plates should be
provided?

20/03/2020
Supplement the Test Principle before Test Procedure
shall be applied.
20/03/2020
Ground condition should be hard or using steel plate
where the crane placement.

20/04/2020
When the crane moving or standby to loading or
unloading concrete block or heavy equipment, should
be used four steel plate.

Page 13 of 15


Comment Response Sheet (CRS)
47

Page 24

03/03/2020
Supplement the Interpreting and Analyzing Measured
Data

20/03/2020
The interpreting and Analyzing Meassured Data will be
submitted after finish testing.

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

Closed
O

03/03/2020

O

01/04/2020

Closed
O

03/03/2020

O

01/04/2020

O
Closed

01/04/2020
Closed
48

Page 26

03/03/2020

Unauthorized people ?

20/03/2020
Yes it is. Corrected.

01/04/2020
Closed
49

50

51

Page 26

Page 26

Page 26

03/03/2020
How is adequate?

20/03/2020
Attained standard requirement about lighting for
Worker could see clearing their working in night .

01/04/2020
49. OPEN. it is recommended 100 lux to 300 lux at
working areas, 30 lux to 80 lux at common areas

20/04/2020
The light for small working area with 30 lux to 80 lux.

03/03/2020
Please describe approved dump yard area, the license
should be attached

20/03/2020
Dump yard area where the place had been permitted
and licensed.

01/04/2020
50. OPEN. This information shall be reflected in this
document for site implementation and provide the clues
for review

20/04/2020
The disposal soil will be move to dump yard area
which permitted by Owner or move disposal soil out
site where it had licensed and approved by Owner.

03/03/2020
How to deal with fuel leakage/spill?

20/03/2020
With fuel leakage/spill need to using rag to clean or if
fuel leakage to ground should be used shovel move it
to trash can.

01/04/2020

51. OPEN. This information shall be reflected in this
document for site implementation and provide the clues
for review and oil spill kit should be provided

20/04/2020
With fuel leakage/spill need to using a tray to contain .
If fuel leakage full in tray,it will be moved to oil can
and the third party who have licensed to move this oil
used out site.

Page 14 of 15


Comment Response Sheet (CRS)
52

53

54

Page 26

Page 26

Page 27

03/03/2020
How about smoking?
01/04/2020
Closed

03/03/2020
Please add "other PPE is provided if necessary", such
as "facial shield" for welder.
01/04/2020
Closed
03/03/2020
1. This job safety analysis and it is not risk assessment,
It is recommended that EPC shall prepare the risk
assessment pertain to method statement.
2. At least, following steps shall be described in the risk
assessment: Mobilization of equipment, material unloading - essential of equipment (drilling machine,
mixing station, temporary electric) - moving and setting
drilling machine at drilling point with steel plate - drilling
and excavating including splicing - mixing and pumping
slurry - lifting and inserting the PHC pile - moving,
lifting and setting the counterweight - execution of load
test - dismantle and the load test system demobilization - any other complement activities.
3. It seem that there is no EPC's HSE team review on
this document. It is recommended that EPC's HSE team
have to review this kind of document before sending
out.
01/04/2020
54. OPEN. the risk assessment in this MS did not follow
VP1-C-L4-H-GEN-00003 HSE Risk Management
procedure. If someone from L4's HSE team has review
this document before sending. it mean he has no
expertise.

20/03/2020
No smoking on site, Smoking at the Relax area.

20/03/2020
Other PPE is provided if necessary.

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

C

03/03/2020

O

01/04/2020

Closed
O

20/03/2020

Risk assessment is updated in the document.

20/04/2020
The risk assessment for this MS follow HSE Risk
Management procedure will be attached in attachment
#3

Additional Notes (if any)
* O - Open, C – Closed

Page 15 of 15


AP

APPROVED
Approved

AC

APPROVED WITH COMMENT
Contractor to revise the correction and resubmit

NA

NOT APPROVED
Revise the correction and resubmit before proceeding

RE

REVIEWED

For Approval

Information acknowledged with no comment

RC

REVIEWED WITH COMMENT
Information acknowledged with comments

Note: Approval or comment does not relieve the Contractor of
all obligations covered under contract

Discipline: Civil
27 Apr 20
Date:

C

22-Apr-2020

For Approval

J.H CHOI

K.S KIM

Y.J Lee

B

20-Mar-2020

For Approval

J.H CHOI

K.S KIM

D.H Jeong

A

20-Feb-2020

For Approval

J.H CHOI

K.S KIM

D.H Jeong

REV

DATE

DESCRIPTION

Approved

Checked

Prepared

OWNER

VAN PHONG POWER COMPANY LIMITED
PROJECT

Van Phong 1 BOT Thermal Power Plant Project
Status
□Approved
□Approved with Comment
□Not Approved
□Reviewed

OWNER’S ENGINEER
Pöyry Switzerland Ltd.
EPC CONTRACTORS

IHI–TESSC–CTCI–DHI CONSORTIUM

PROJECT DOCUMENT No

REV

VP1-0-L4-C-GEN-10017

C

DOCUMENT TITLE

METHOD STATEMENT FOR TEST PILLING WORK (Pre-boring PHC Pile)
EPC

EPC DOCUMENT No.
VP1-0-L4-C-GEN-10017

Doosan Heavy Industries and Construction
1|Page

REV
C


VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

CONTENTS

1. PREFACE ............................................................................................................................. 3/56
2. APPLICATION ............................................................................................................... .. 3/56
3. PURPOSE OF TEST PILE ................................................................................................. 3/56
4. SCOPE OF WORK............................................................................................................... 3/56
5. REFERENCES ................................................................................................................... 4/56
6. SCHEDULE……………………………………………………………….......….. ……....5/56
7. SITE ORGANIZATION……………………………..………………………………….…6/56
8. MOBILIZATION PLAN OF WORKFORCE ...................................................................... 6/56
9. MOBILIZATION PLAN OF CONSTRUCTION HEAVY EQUIPMENT ......................... 7/56

10. MATERIAL .......................................................................................................................... 7/56
11. CONSTRUCTION METHOD ............................................................................................. 8/56
12. STATIC LOAD TEST ........................................................................................................ 36/56
13. TENSILE LOAD TEST .................................................................................................... 42/56
14. HORIZONTAL STATIC COMPRESSION TEST .......................................................... 46/56
15. HIGH STRAIN DYNAMIC LOAD TEST ....................................................................... 50/56
16. QUALITY CONTROL ..................................................................................................... 52/56
17. ENVIRONMENT, HEALTH AND SAFETY .................................................................. 53/56
18. ATTACHMENT ............................................................................................................... 54/56

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VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

1. PREFACE
Herewith we submit this method statement that describes implementation plan for the test
pilling work. DHI intends to execute this working a safe, reliable condition achieving best
quality of construction.
 Project

Van Phong 1 BOT Thermal Power Plant

 Company/Owner

Van Phong Power company limited(VPCL)

 Contractor

DHI

2. Application
Application of this Method Statement is limited to the scope of test piling of Pre-boring
PHC piling works.

3. Purpose of test pile:
Determine the characteristic value of the pile and provide test parameters for engineering pile
foundation.
a. The compressive and lateral load test measures the vertical and lateral deformation of
the deep foundation.
b. The tension (uplift) load test is performed to determine axial tensile (uplift) load
capabilities of piles.

c. The Dynamic load testing is used to provide data on strain, force, acceleration,
velocity, and displacement of a pile under an axially applied impact force.
4. Scope of work:
The scope of test piling work is the static load tests and dynamic load test which is conducted
for one PHC D800 type B pile and two PHC D600 Type A. Detail location is shown on the
Attachment #1 VP1-0-L4-C-GEN-00021 PRELIMINERY TEST PILE PLAN PLOT PLAN
for reference. Test pile location shall be complied with VP1-0-L4-C-GEN-00021
[Table : List of test pile]
Pile Diameter
D800 – Class B
D600 – Class A
D600 – Class A

3 | Page

Quantity of
test pile

3
3
3

Location
Chimney
Coal Storage
Water Treatment

Kind of testing pile
Vertical, Lateral and Uplift load test
Vertical, Lateral and Uplift load test
Vertical, Lateral and Uplift load test


VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

The pile PHC D600 Type A and D800 Type B for production pile is shown on the Attachment
#2 Drawing of PHC-D800 and PHC-D600.

5. REFERENCE
a. JIS A5373-2010 “Pre-stressed Spun Concrete Piles (PHC pile)”
b. TCVN 7888-2014 Pre-tensioned spun concrete pile.
c. TCVN 10667-2014 Spun concrete pile – Pile drilling and Installing – Construction
and acceptance.
d. TCVN 9393-2012 Piles – Standard test method in situ for piles under axial
compressive load.
e. TCVN 9394 : 2012 Pile Pressing and Driving – Standard for construction, checking
and acceptance
f.

ASTM D 1143 - “Standard test method for Deep Foundations under Static Axial
Compression Load”

g. ASTM D 3689 - “Standard test method for Deep Foundations under Static Axial
Tensile Load”
h. ASTM D 3699 - “Standard test method for Deep Foundations under Lateral Load”
i.

4 | Page

ASTM D 4945 - “Standard Test Method for Pile under PDA/DLT”


VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

6. Schedule

5 | Page


VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

7. Site organization

8. MOBILIZATION PLAN OF WORK FORCE
Assigned Position

Number
1

1
1
2
1
1
2

Foreman
Crane driver
Drilling and drive machine driver
Welders
Mixing Machine operator
Surveyors
General labors

Remarks

Mixer and Pump, etc.

MOBILIZATION PLAN OF CONSTRUCTION HEAVY EQUIPMENT
Heavy Equipment
Crawler Crane
Upper auger
Under auger
DH608-120M(Base machine)
Mixing machine
Excavator
Compressor
Air hammer
Electric Generator

Generator for Base machine
6 | Page

Number
1
1
1
1
1
1
1
1
1
1

Capacity
150T
9T
14T
65T
7T
15T
9T
3T
3.7T
3.7T

Remarks

Consist of Mixer and Pump,.etc

.
If needed


VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

9. MOBILIZATION PLAN OF TESTING EQUIPMENT
Testing Equipment
Hydraulic jak
Hydraulic pump
Pressure gauge
Displacement Transducers
Reference beam
Test beam
Cross beam
Kentledge

Number
02
01
01
01
02
01
06
01

Manufacture

Remarks

USA
USA
Holand
USA

10. MATERIAL
10.1

Hardening Cement Milk Grouting

Mixing & Strength Test
-

-

7 | Page

Compressive strength test should be carried out at laboratory & site
(R28>=20Mpa)
During mixing, the concrete temperature should be managed constantly.
Mix design and raw material for pile D600A, pile length 20m and Drilling holes
diameter D700.
Cement

2400 kg

Water

1700 L

Compressive Strength

200 kg/cm2

Mix design and raw material for pile D800B, pile length 20m and Drilling holes
diameter D900.
Cement

3,330 kg

Water

2,330 L

Compressive Strength

200 kg/cm2


VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

10.2

PHC Pile
Piles shall be manufactured in accordance with JIS A 5373
(or equivalent Vietnamese code)

90

Compressive
Strength of
Concrete
(N/mm2)
80

Allowable
Axial
Force
(tonf)
155

110

80

300

Class

Effective Prestress
(N/mm2)

Thickness
(mm)

600

A

4.0

800

B

8.0

No.

Diameter
(mm)

1
2

11. CONSTRUCTION METHOD
11.1

Description

Using Auger Drill Machine, a pre-drilled hole is obtained where hardening cement slurry
is filled to harden the root soil at the pile tip. PHC (Pre-tensioned High strength Concrete)
precast piles that are manufactured at the shop are to be inserted inside the hole. Pile
fixing slurry is filled into the gap in order to enhance friction force between pile and the
surrounding soils. Several light blows on the pile head should be subsequently conducted
in order to secure the bearing layer at the pile tip elevation.
11.2

Working Procedure

a. Drill to the design depth with spiral auger, the diameter of borehole shall be 10cm larger
than PHC pile diameter.
The slime at the bottom of bore hole could not be treated after completion of drilling.
b. Pull up earth auger, remove some soil cutting, injecting root–hardening cement slurry
through hollow drilling rod with proper pressure after drilling to predetermined depth.
c. Pull out the earth auger completely, inserting the PHC pile into borehole with its own
weight.
d. PHC pile is fixed to the bearing capacity by hammer (The capacity of PHC pile is 6281kN)
(For multi-segment pile, splicing will be applied at a service hole before installing pile).
e. A pile is fixed to bearing layers by the drop hammer.

8 | Page


VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

te Drilling
Hardening

6. Light Blow

5. Pile Insertion

4. Completion of Pre-drilled hole

3. Auger pulling up

2. Slurry Injection

1. Auger Drilling

Light Blow
BlowBentoni

cement

Auger could not be in the slurry during injection of grout. The auger will withdraw when
pump slurry into hole.

f.
11.3

Excavating soil with air compressor

a. Excavating soil from the ground to designed depth by drilling with air compressor.
b. During construction, the excavating soil shall be collected by excavator.

[Excavating Soil to Designed Depth
By Double Auger Machine]

c. Borehole will be kept as vertical during drilling. .
11.4

Cement Milk Grouting

Before and after pile-inserting into the hole, hardening cement milk grouting shall be filled
respectively. After excavation reach to the designed depth, the cement milk grouting shall
be injected into the borehole. Cement milk grouting will be mixed at mixing machine
based on approved mix design. Root milk grouting goes through drilling rod to bottom of

drilled hole with designed volume. Fixed milk grouting to be pumped from top of
borehole after inserting pile will be filled in the gap between pile and wall of hole due to
cement will be deposited after one day. Cement milk grouting take a role in strengthening
bearing capacity at pile tip and recovering & rebounding side friction of pile.
Cement milk grouting should be complied with requirement of JRA code. The time for
slurry to get hard is approximately 2 ÷ 4 hours (According to mechanical target of Cement
PCB40 of Nghi Son using at site).
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VAN PHONG 1 BOT THERMAL POWER PLANT PROJECT

11.5

Installing pile

a. After the filling up cement milk grouting is completed, the PHC pile shall be installed
immediately into the borehole to the designed depth.
b. Pile shall be settled slowly by service crane
c. Two perpendicular vertical directions will be controlled by mean of plumb-line and
theodolites to adjust position and direction of piles. The verticality of pile shall be
observed by the theodolites
d. Before installing the pile, the ground shall be made evenly. The flat working ground
shall minimize the displacement of pile.

[Installing pile by crane and pile is fixed to the bearing capacity layer by light hammering]
e. After installing pile, the Cement Milk will over flow on the ground, at that time the
Cement Milk will flow to the gutter had been excavated.
f.

When Cement Milk over flow on the ground, Ground water inside the borehole will
be pushed out with gravitation of Cement Milk due to graviation of Cement Milk
heavier than ground water.

g. Using light blow driving pile head until fix to the ground and then using two direct
which have been located at the near distance to check vertical of pile head.
h. Vertical tolerance of pile will be applied in TCVN 10667 at page 18 item 9.2.8
indicated the vertical tolerance is 1% of pile length are accepted.

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