សូមអរគុណចំពោះលោកសាស្រ្តាចារ្យ សៀង ពៅចំពោះការចែករំលែកដ៏មាន តម្លៃ និងមានអត្ថន័យ។ សូមជូនពរលោក សាស្រ្តាចារ្យអោយមានសុខភាពល្អ..!!

1. Kingdom of Cambodia
National Region King
National Polytechnic Institute of Cambodia
Faculty of Civil Engineering
Paper research of piles foundation
In Phnom Penh capital of Cambodia
Phnom Penh October 11, 2011

2. This present paper research was prepared by Mr. Sieng PEOU Master Science
of geotechnical engineering and lecturer of geotechnical engineering in department
Geo-resources and Geotechnical Engineering of Institute of Technology of Cambodia
(ITC).
Acknowledgements
I would like to firstly express my deepest thanks and gratitude to Dr. Suen
SAMBAT deputy director of International University for his kindness, valuable
support, encouragement, and helpful guidance of this paper research. He always
shared his valuable time to cooperatively discuss my research when I needed his help.
I consider it to be great fortune to have had the opportunity to work with him and also
the best experience in conducting the research.
Furthermore, I would like to extend my grateful thanks to Mr. Iv MONY the
director of Research and Design Enterprise for his helpfulness and kindness provided
all possibility for complete this research.
My sincere gratitude is extended to Dr. OM Romony Director of Institute of
Technology of Cambodia, who always supported and encourages me to do this
research.
Moreover, my great thanks are given to all lecturers of Department of Geo-
resources and Geotechnical Engineering for their motivation, care, help, discussion
and friendship.
And at last I would like to thanks to Ministry of Land and Management of
Cambodia and Research & Design Enterprise, who supported the fund for this
research.
Abstract
In the last time the driven pile and bored pile foundation are widely used in
Cambodia. And for calculation the bearing capacity of bored pile foundation we have a lot of
equation for resolve it by using soil parameter from laboratory testing and by using in situ test
like static cone penetration test, dynamic cone penetration test, pressiometer test and standard
penetration SPT.
The problem for us is the inability to take undisturbed sample at the greater depth like
for the sandy soil, so the capacity of our laboratory can not provide sufficiently soil data for
calculates the bearing capacity of pile foundation. So we need equation and safety factor
suitable for the sub-soil condition in Cambodia by using index SPT.
For verifying the bearing capacity of bored pile and driven pile foundation we need
static pile load test.
The research was done in the construction of the Ministry of Land and Management
of Cambodia for bored pile and in Sport City, street No211, Sangkat Vealvong, Khan 7
Makara, Phnom Penh city for driven pile.
Keywords
Bored pile foundation, driven pile, Standard Penetration Test (SPT), pile load test,
bearing capacity.

3. Introduction
The bearing capacity of driven pile and bored pile foundation is the problem very
important in Cambodia. The level of research on condition of geotechnical engineering in
Cambodia is not yet sufficiently for estimation the bearing capacity of soil foundation in this
country. In this research we try to find suitable equation and safety factor of bored pile
foundation in Phnom Penh capital of Cambodia. The location of research is located in Phnom
Penh Capital of Kingdom of Cambodia.
For verifying the bearing capacity of driven pile and bored pile foundation we need
static pile load test.
For bored pile the test was done in the construction of the Ministry of Land and
Management of Cambodia.
For driven pile the test was done in Sport City, street No211, Sangkat Vealvong,
Khan 7 Makara, Phnom Penh city.
I-Research on Bored pile foundation:
The test divided in two steps:
-Step 1: Soil boring and SPT testing in the boring hole.
-Step 2: Static pile load test on bored pile foundation by Quick Maintained
Load.
For step 1 we bored 5 boreholes with the depth 35.00m and done the SPT test every
1.50m. We also collected the soil sample for testing in the laboratory condition.
The soil investigation was carried out on August, 10, 2009.
I-1-Soil boring and take soil sample for testing in laboratory condition:
I-1-1-Field work
 Boring and take the undisturbed and disturbed sample
 Standard penetration test in boring hole
 Shear vane test in boring hole
 Pocket penetration test on undisturbed sample
 Pocket shear vane test on undisturbed sample
I-1-2-Laboratory testing
 Water content
 Atterberge limits
 Specific gravity
 Soil particle size
 Unconfined compression test
 Direct shear test
 Consolidation test
The testing-procedure was conducted in accordance with ASTM Standard and
classified soil by USCS.

4. I-2-SPT testing in the boring hole:
Standard Penetration Test was carried out 1.50m intervals inside the each
boring hole. A standard split spoons of 50.8mm diameter with a ball check valve on
the top and harden steel cutter. A Standard spilt spoon was installed and drives into
the soil by a 63.5kg automatically drop hammer falling freely from a fixed height of
760mm along a guide rod.
The blow counts defined for each 150mm penetration of the seating drive. The
total penetration of the spoon is 450mm and the numbers of blow N-value for last
300mm. Penetration was recorded as the N-value of the soil stratum encountered
which indicated the relative density of non-cohesive soil as well the consistency of the
cohesive soil.
I-3- SAMPLING
I-3-1-Undisturbed samples: Undisturbed samples were taken in the natural
state of the soil from firm to stiff clay and sandy clay. The undisturbed samples were
taken by thin wall tube sampler in the natural state.
I-3-2Disturbed samples: The disturbed samples were taken at a rate of 1.5m
and all strata in the each borehole. The disturbed samples were also collected in soft
to stiff clay and sandy soil.
The relation between S.P.T result and Consistency
for Clay, Silt, Clayed-Silt and Silty-Clay (Cohesion Soils)
Table 1
S.P.T N Value (blows/ 300mm) CONSISTENCY
0 to 2 Very soft
2 to 4 Soft
4 to 8 Medium Stiff
8 to 15 Stiff
15 to 30 Very Stiff
30 over Hard
The Relation between S.P.T Result and Relative Density
For Sand and Gravel (Cohesion less Soil)
Table 2
S.P.T N Value (blows/ 300mm) RELATIVE DENSITY
Less than 4 Very loose
4 to 10 Loose
10 to 30 Medium dense
30 to 50 Dense
Over 50 Very dense

5. I-4-GROUND CONDITION AND SOIL PROPERTIES
For this site the ground condition from the ground surface to 35.00m depths
consisted of filling process of Mekong River was in 4th Era (Young alluvium). The
soil condition encountered on boreholes has been into strata as follows:
BOREHOLE No 5
Stratum N-value
No Blows /300mm
Description of soil strata
1 - Made ground, encountered from top to 2.00m depths.
2 - Brown stiff Lean CLAY, encountered from 2.00m to 4.20m. N-12
3 - Grey medium dense Fine SAND, encountered from 4.20m to 5.30m. N-16
4 - Grey loose Fine SAND, encountered from 5.30m to 8.50m. N-9; N-10
- Grey medium dense Fine SAND, encountered from 8.50m to
5 N-29
10.30m.
6 - Yellow dense Clayey SAND, encountered from 10.30m to 13.50m. N-49; N-43
- Grey very stiff Lean CLAY with sand, encountered from 13.50m to
7 N-28
14.60m.
8 - Yellow very dense Fine SAND, encountered from 14.60m to 15.80m. N-69
9 - Grey dense Fine SAND, encountered from 15.80m to 17.70m. N-41
10 - Yellow very stiff Fat CLAY, encountered from 17.70m to 20.50m. N-24; N-25
11 - Yellow dense medium SAND, encountered from 20.50m to 21.70m. N-50
12 - Yellow hard Lean CLAY, encountered from 21.70m to 23.70m. N-37
13 - Yellow dense medium SAND, encountered from 23.70m to 25.00m. N-41
14 - Yellow dense Clayey SAND, encountered from 25.00m to 28.20m. N-47; N-34
- Yellow very dense Clayey SAND, encountered from 28.20m to
15 N-55; N-61
30.70m.
- Yellow very hard Fat CLAY with sand, encountered from 30.70m to
16 N-62; N-69; N-
35.00m. 74

7.  On basis of field observation, it appears reasonable to standardize the field
penetration number as a function of the input driving energy and its dissipation
around the sampler into the surrounding soil, or
N . H . B . S . R
N 60 
60

8. Based on recommendation by Seed et al.(1985) and Skempton(1986)
1-variation of H
Country Hammer type Hammer release
H
Japan Donut Free fall 78
Donut Rope and pulley 67
United State Safety Rope and pulley 60
Donut Rope and pulley 45
Argentina Donut Rope and pulley 45
China Donut Free fall 60
Donut Rope and pulley 50

9. 2-variation of B
Diameter
B
mm In.
60-120 2.4-4.7 1
150 6 1.05
200 8 1.15
3-variation of s
Variable
s
Standard sampler 1
With liner for dense sand and clay 0.8
With liner for loose sand 0.9
4-variation of R
Rod length
R
m ft
>10 >30 1
6-10 20-30 0.95
4-6 12-20 0.85
0-4 0-12 0.75

10. I-5-Bored pile bearing capacity from SPT :
We used the equation Shioi and Fukui (1982) for calculation the End Bearing
Capacity of bored pile foundation. And for calculation the skin friction we were used
two methods, the equation Findley (1984) and Shioi and Fukui (1982) and the
equation Wrigth and Reese (1982):
I-5-1-End bearing capacity:
-After Shioi and Fukui (1982)
1-for coarse grained soil
qP=100N60(KPa)
2-for fine grained soil
qP=150N60(KPa)
So Qp=qP.AP(KN)
I-5-2-Skin friction For coarse grained soil:
-After Findley (1984) and Shioi and Fukui(1982) : qf=N60(KPa)
-After Wright and Reese (1979) :
qf=3.3N60(KPa)
I-5-3-Skin friction For fine grained soil:
-After Decourt (1982) :
qf=10+3.3N60(KPa)
The results after testing shown as follow:
1-If we choose the equation Findley (1984) and Shioi and Fukui(1982) for
calculate the skin friction we can find the ultimate bearing capacity for bored
pile with dimension diameter D=1.00m and 31.00 m length:
QU=9900KN. So for safety factor 2.0, we have allowable bearing capacity
Qall=4950KN
2-If we choose the equation Wrigth and Reese (1982) for calculate the skin
friction we can find the ultimate bearing capacity for bored pile with dimension
diameter D=1.00m and 31.00 m length:
QU=14726KN. So for safety factor 3.0, we have allowable bearing capacity
Qall=4909KN

11. For step 2 we prepared the static pile load test by Quick Maintained Load
method.
I-6-Pile load test
The pile load test was carried out on October, 23, 2009.
-for verifying the bearing load for bored pile with D=1.0m and L=31.0m.
-for comparing the equation were used in the report of soil investigation.
Pros versus Cons of load testing a pile:
-Load testing is the most accurate way to determine the ultimate compressive and
tensile capacities for deep foundations.
-Load testing is expensive and time consuming.
I-6-1-The testing procedure:
The test load shall be conforming to the Modified ASTM D 1143/D1143M-07
Item8.1.3 Procedure B with the load sequence, in percent of design load as shown
bellows:
1st cycle
0% --> 25%- ->50%-- >75%- -> 100%(*)- -> 50%-->25%- -> 0%(**)
2nd cycle
0%- -> 25% -->50%-- >75%- -> I00%- -> 125%- -> 150%- -> 175%-- >200%(*)- ->
l50%-->100%- -> 50%- -> 0%(**).

12. I-6-2-Condition test:
-Maintain each load in cycle 1 and 2 until the rate of settlement is less than
0.25mm./hr but not more than 2 hours which ever occurs first.
-Maintain maximum test load( *) in cycle 1 and 2 for 12 hours if the rate of
settlement over a one-hour period is not greater than 0 .25 mm./hr, otherwise maintain
the maximum test load for 24 hours.
-Released the test load in cycle 1 and 2 every 1 hour and maintain zero load
(**) until recovery rebound stop but not more than 12 hours,
-Take reading of time Load and settlement in cycle1 and 2. Record them just
at 0, 5,10,15,20,40,60,80,100 and 120 minutes and every 1 hour for the next 10 hours
and every 2 hours thereafter.
I-6-3-Test result:
The interpretation of test results shall comprise of:
-Pile Description
-Tabulation of test data: time, load and movement of test pile head.
-Load-Settlement curve
-Time-Load curve
-Time-Settlement curve
-Conclusion
- etc..
I-6-4-Final result:
The final result of pile testing is presented in the table as follow:
Q-apply load (KN)
-final settlement (mm)
Q (mm)
0 0
1065 0.69
2130 1.69
3195 2.65
4260 3.91
5320 5.35
6390 6.55
7455 10.05
8520 18.29

13. I-6-5-Estimate pile bearing capacity from Davisson’s method:
0 1000 2000 3000 4000 5000 6000 7000 8000 9000
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
I-6-6-Plot line =(QL)/(AE)
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35

14. I-6-7-Offset limit load straight line OC=3.8+D/120
After the calculation the ultimate bearing capacity of bored pile foundation
from pile load test result by using Davisson’s method, we find 0.9Qu=8850KN, so
Qu=9833KN
For pile load test we take the safety factor FS=2, so
Qall=4917KN

16. I-6-8-Summaries of research
Method Qu FS Qall
(KN) (KN)
Pile load test result 9833 2 4917
Equation Wright and 14726 3 4909
Reese
Equation Findley and 9900 2 4950
Shioi and Fukui
I-6-9-Conclusion
The conclusion after the study is presented as follow:
- The equation Wright and Reese (1979) find the same result as pile load test
when we take safety factor FS=3.
- The equation Findley (1984) and Shioi and Fukui (1982) find nearly the
same result as pile load test when we take safety factor FS=2.

17. II-Research on Driven pile foundation:
The test also divided in two steps:
-Step 1: Soil boring and SPT testing in the boring hole.
-Step 2: Verified pile bearing capacity by pile driven equation
-Step 3: Static pile load test on bored pile foundation by Quick Maintained
Load.
For step 1 we bored 8 boreholes with the depth 15.00m and done the SPT test
every 1.50m. We also collected the soil sample for testing in the laboratory condition.
The soil investigation was carried out on November, 07, 2007:
1-Soil boring and take soil sample for testing in laboratory condition.
2- SPT testing in the boring hole.
BOREHOLE Nº 2
Stratum 1: Made ground, present from 0.00m to 2.00m depths.
Stratum 2: Brown soft sandy clay, present from 2.00m to 5.20m depths.
Stratum 3: Yellow stiff lean clay with sand, present from 5.20m to 7.00m depths.
Stratum 4: Loose clayey fine sand, present from 7.00m to 8.00m depths.
Stratum 5: Medium dense clayey silty fine sand, present from 8.00m to 9.80m depths.
Stratum 6: Grey dense clayey fine sand, present from 9.80m to 14.20m
Stratum 7: Yellow stiff lean clay, present from 14.20m to 15.00m depths.

19. II-1-Driven pile bearing capacity from SPT:
We used the equation Decourt (1982) and Matin et al(1987) for calculation the End
Bearing Capacity of driven pile foundation:
II-1-2-End bearing capacity:
1-for coarse grained soil by Decourt (1982)
qP=400N60(KPa)
2-for Clay by Matin et al(1987)
qP=200N60(KPa)
3-for Silt and sandy Silt by Matin et al (1987)
qP=350N60(KPa)
And for calculation the skin friction we were used equation Meyerhof (1956) Decourt
(1982):
II-1-3-Skin friction:
-Meyerhof equation (1956) for Sand:
qf=2N60(KPa)
-Decourt equation (1982) for mixed soil:

20. qf=10+3.3N60(KPa)
-Shioi and Fukui equation (1982) for Clay :
qf=10N60(KPa)
The results after testing shown as follow:
After the study we obtained the result as follow:
1- The ultimate bearing capacity for driven pile with dimension diameter
B=0.30m and 11.00 m length: QU=1358.88KN. So for safety factor 4.0, we have
allowable bearing capacity
Qall=339.7KN
For step 2 we verified the pile berating capacity by pile driven equation:
II-Pile bearing capacity from pile driven method:
II-1-Modified ENR equations
EWR h WR  n 2WP
Qu  ( )( )
S  C WR  WP
II-2-Michigan state highway commission equations
1,25EH E WR  n 2WP
Qu 
S  C WR  WP
II-3-Danish equations
EH E
Qu 
EH E L
S
2 AP EP
II-4-Pacific Coast Uniform Building Code equations
 W  nWP 
( EH E ) R
 W W 

Qu   R P 
Qu L
S 
AP E P

21. II-5-Pile driven data
E-hammer efficiency=0.8
Ep- elastic modulus of the pile=21000000KPa
h-height of fall of the ram=0.8 M
S-penetration of the pile per hammer blow=0.0083 (M)
WR-Weight of the ram=50 KN
WP-weight of the pile=24.75 KN
n- Coefficient of restitution between the ram and the pile cap n=0.4 except
equation pacific coast uniform building code n=0.1
C=0.00254 M
Hammer type Efficiency,E
Single and double acting hammers 0.7-0.85
Diesel hammers 0.8-0.9
Drop hammers 0.7-0.9
Pile material Coefficient of restitution
n
Cast iron hammer and concrete pile 0.4-0.5
without cap
Wood cushion on steel pile 0.3-0.4
Wooden pile 0.25-0.3

22. II-6-Results of pile driven bearing capacity from pile driven equations
Method Ultimate bearing Safety Allowable
load (KN) factor bearing load
(KN)
Modified ENR equation 2124.46 6 354.076
Michigan state highway 2655.57 6 442.595
commission equations
Danish equations 1779.43 5 355.886
Pacific Coast Uniform 1375.09 4 343.773
Building Code equations
For step 3 we prepared the static pile load test by Quick Maintained Load method and
we obtained the result as follows:
The pile load test was carried out on January, 20, 2008:
1-for verifying the bearing load of driven pile with B=0.3m and L=11.0m.
2-for comparing the equation were used in the report of soil investigation.
II-7-Result of pile load testing
The final result of pile testing is presented in the table as follow:
Q-apply load (KN)
-final settlement (mm)
Q  (mm)
0 0
83.5 0.69
167 1.69
246.9 2.65
330.4 3.91
493.8 5.35
577.3 6.55
660.8 10.05
740.6 18.29

23. II-8-Estimate pile bearing capacity from Davisson’s method:
0 100 200 300 400 500 600 700 800 900 1000
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
II-9-Plot line =(QL)/(AE)
0 100 200 300 400 500 600 700 800 900 1000
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35

24. II-10-Offset limit load straight line OC=3.8+D/120
After the calculation the ultimate bearing capacity of bored pile foundation from pile
load test result by using Davisson’s method, we find 0.9Qu=600KN, so
Qu=666.66KN
For pile load test we take the safety factor FS=2, so
Qall=333.33KN

25. II-11-Summaries of research
Method Qu FS Qall
(KN) (KN)
Modified ENR equation 2124.46 6 354.076
Michigan state highway 2655.57 6 442.595
commission equations
Danish equations 1779.43 5 355.886
Pacific Coast Uniform Building 1375.09 4 343.773
Code equations
Pile load test result 666.66 2 333.33
SPT test result 1358.88 4 339.70
According to this research we check the pile driven in Phnom Penh area, and we
obtained the results as follows:
Result pile driven test in KOKI district, Phnom
Penh.
Pile length L=21m and pile size B=0.3m
Method Ultimate Safety Allowable
bearing load factor bearing load
(KN) (KN)
SPT 1356.24 4 339.1
Modified E NR equation 2511.94 6 418.65
Michigan state highway 3139.93 6 523.32
commission equations
Danish equations 1745.45 5 349.09
Pacific Coast Uniform 1067.78 4 266.94
Building Code equations

26. Result pile driven test in Vealsbov district,
Phnom Penh.
Pile length L=21m and pile size B=0.3m
Method Ultimate Safety Allowable
bearing load factor bearing load
(KN) (KN)
SPT 1316.64 4 329.2
Modified E NR equation 2466.89 6 411.14
Michigan state highway 3083.61 6 513.93
commission equations
Danish equations 1787.73 5 357.5
Pacific Coast Uniform 1154.63 4 288.65
Building Code equations
II-12-Conclusion
The conclusion after the study is presented as follow:
1- If we choose method SPT for determine the bearing capacity of driven pile
foundation in Phnom Penh area we need the safety factor of 4.
2-After testing on driven pile in Phnom Penh area, we can find that:
-for short pile all the driven equation find nearly the same results.
-for long pile, the Danish equation is always verified with SPT
method but for another equation showed very varied results.
3- This research is limited for data pile load test in Phnom Penh city only.
This research paper prepared by Prof. Sieng PEOU
Master science of geotechnical engineering
Lecturer of geotechnical engineering in department
Geo-resources and Geotechnical Engineering
Institute of Technology of Cambodia
Email: sieng_2000@yahoo.fr
Tel:(855)11 874 974
Phnom Penh October, 11, 2011

27. Reference:
1-Principles of foundation engineering Sixth Edition Braja M. Das 2007
2-Soil mechanics and foundations First Edition Muni Budhu 2000
3-Results Soil investigation done by Research and Design Enterprise
4-Results Static pile load test done by Innovation Engineering Service
5-Davisson, M. T., “High capacity piles". Proceedings of Lecture Series on
Innovations in Foundation Construction, American Society of Civil Engineers, ASCE
6- Emerging Technologies in Structural Engineering
Proc. of the 9Th Arab Structural Engineering Conf., Nov. 29 - Dec. 1, 2003, Abu
Dhabi, UAE