Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

Study on the Horizontal Bearing Performance of Steel Tubular Piles Installed by
the Gyropress Method and the Press-in Method Assisted with Water Jetting
Naoki SUZUKI
Construction Solutions Department, Giken Ltd., Japan
Email: suzuki.n@giken.com

Yasumasa KIMURA
Construction Solutions Department, Giken Ltd., Japan

ABSTRACTIn this paper, the results of static horizontal loading tests of steel tubular piles installed by the Gyropress Method and thePress-in Method assisted with water jetting were collected, and these horizontal bearing performances were evaluated.
As a result, the following were drawn: 1) Load-displacement curves of the Press-in Method assisted with water jetting
and the Gyropress Method were consistent with the Weibull distribution curve, when the deformation index m=1.0. The
average yield displacement normalized by the pile diameter with the Gyro Method is consistent with the average valuesof 4.1 – 4.5 % for steel tubular piles installed by other construction methods, and that with the WJ Method gives smaller
value than the average of other construction methods; 2) The coefficient of horizontal subgrade reaction calculated
backward from the displacement at the loading point showed somewhat larger value than the design value when thereference displacement was set at 1 % of the pile diameter in the case of the Gyro method. On the other hand, for cases
constructed by the WJ method, the average of measured kH is regarded fairly consistent with designed kH, but the variationof them are large; and 3) In the case of group piles, δg - kH curves were better fitted than δg / B - kH curves. The calculated
backward kH approximately coincides with the design kH when the horizontal displacement at the ground surface is about
15 mm.

Key words: Horizontal subgrade reaction, Rotary press-in, Water jet system, Horizontal loading tests, Steel tubular pile

1. INTRODUCTION

subgrade deformation of pile is 1 % of the loading width

1.1. BackgroundAs means to evaluate coefficients of horizontal(JRA, 2017).

subgrade reaction, two methods have been suggested: one

bearing performance is affected by the construction

based on the in-situ horizontal loading tests; andmethod, it has not necessarily been clearly evaluated in thehorizontal resistance calculation equation based on thecurrently available design methods. For example, in the

results of existing horizontal loading tests. It is often thestandard of Ports and Harbours Association of Japancase that the latter is adopted. For the coefficient of(PHAJ, 2007), though it has been described that attention

horizontal subgrade reaction is evaluated from themust be paid to the effect of the construction method,

deformation modulus of the ground and the pile diameter,

especially when the construction might have loosened theas well as it is evaluated in a non-linear relationship that issurrounding ground, how to evaluate the effects is notinversely proportional to square root of the groundconcretely presented.

Although it is considered that the horizontal

deformation. It is prescribed that the reference coefficient

The Press-in Method is one of the constructionof horizontal subgrade reaction be one when the horizontal

methods for the foundation works with steel tubular piles.

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Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

In the method, already installed piles are held by the Silent

where,

Piler, a hydraulic pressing-in/extracting machine for piles,

D: Pile diameter,

B: Foundation width

and the next pile is pressed into ground by a static load,n: Number of piles,

Ld: Embedded depth of pileusing the extraction resistance of already installed piles.

h: Height of loading point

: Characteristic value of foundation (Eq. 3), and

The Press-in Method used in stiff ground include theMethod hereinafter) and the Press-in Method with rotary

Nvalue: Average N-value from the ground surface to -1.
First, bearing performance was approximated by the

cutting (termed Gyro Method hereinafter) (IPA, 2015).

Weibull distribution curve, and evaluated (Uto et al. 1982).

These methods penetrate piles/sheet piles into ground,

The relationship between the yield displacement and the

reducing

Press-in Method assisted with water jetting (termed WJ

construction

foundation width was then checked. After that, thesufficiently small. It has been verified that the reduced

theresistantforce

duringcoefficient of lateral ground reaction force was calculated

ground resistance at the time of pile/sheet pile installation

backward from the displacement at the loading point. The

will recover with time (Shepley & Bolton, 2013). In

calculated coefficients were sorted out for each

addition, it is said that Vibration hammer method withconstruction method and were compared with the design

water jetting for gravel ground affects the surrounding

values. Lastly, the effect of wall width by continuous walls,

ground in the range of up to 30 cm from the outer surface

which is a characteristic of the Press-in Method, to theof the pile (Technical Committee on Vibration Hammer

coefficient of subgrade reaction was checked.

Method, 2015). However, knowledge on the bearing
performance especially in the horizontal direction has notbeen sorted out.

2.2. Piling Method
Constructions by the Gyro Method and the WJ

In addition, the Press-in Method are often used when

Method were carried out as follows; In the Gyro Method,building continuous walls because the Silent Piler use

cutting bits were attached to each pile toe and the pile wasalready installed piles as reaction force. For foundations

installed with rotary cutting. The number of bits of eachwith large widths, researches on horizontal resistance oftest are shown in Table 1 A water pipe was attached inside

structures such as diaphragm walls and large-diameter

the steel tubular pile, and water was supplied, near the pile

caisson piles have been carried out, but few have been

toe location, toward the circumferential as well as outside

conducted on continuous walls with steel tubular piles.

directions. The amount of water flow is described as ‘flow
outside’ + ‘flow inside’ the steel tubular pile in Table 1

1.2. Objectives
The objective of this paper is to understand the(tests D & E).

horizontal resistance characteristics of the Gyro and WJ

outside the steel tubular pile, and the penetration was

Methods, and to check the effect of foundation width tocompleted spurting water to the load bearing layer. The

their horizontal bearing performance .

amount of water flow is described as the maximum flow

In the WJ Method, water jetting pipes were attachedper pipe times the number of pipes in Table 1 (tests G, H
2. METHODS

and I). Note that in all the test piles calculated βLd were

2.1. Overview

bigger than 2.25, and that the evaluation and analysis were

Among the piles penetrated into ground by the Gyro
and WJ Methods, the results of static horizontal loading

carried out, assuming that the piles were embedded tosemi-infinitely long depth.

tests were collected, and their bearing performance were
evaluated.

2.3. Site and Ground Conditions

The data used were 6 cases from the Gyro Method

Fig. 1 shows soil classification and SPT N-value at eachand 3 cases from the WJ Method. In addition, a set of data

location of pile loading tests. SPT N averaged over thefrom Bored Pile Method that was tested at the same site

depth from the ground surface to calculated -1 is shown

were used for comparison. The specifications of eachin Table 1 The -1 were obtained from Eqs. (3) to (7).

testing pile are summarized in Table 1.

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Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

Table 1.

Pile conditions

test

Means*

D

thickBitn water flow
Curing
ness
No.

B

Ld

h

Nvalue

unit

-

mm

mm

-

L/min

-

days

m

m

m

-

A

Bored

600

12

1

-

-

14

0.6

9

0.5

9.1

3.4

B

Gyro

600

12

1

unknown

3

24

0.6

9

0.5

9.1

3.4

C

Gyro

600

12

3

unknown

3

17

2.2

9

0.5

9.1

3.2

D

Gyro

1,000

22

1

20+40

6

29

1

10

2.4

9.9

2.4

E

Gyro

1,000

12

1

20+40

6

26

1

10

2.4

9.5

2.7

F

Gyro

1,000

12

4

unknown6

over 29

4.75

14

2.4

9.1

5.0

G

WJ

800

12

1

325x4

-

over 8

0.8

36.5

0.6

3.3

H

WJ

800

12

1

900x4

-

224

0.8

51

0.6

3.5

Omori etal. (2003)
Ground improvement Fujiwara et
12.6 (pre-vertical loading) al.(2015)

I

WJ

800

12

1

900x2

- unknown

0.8

15.5

0

5.2

4.3

J

Gyro

800

16

1

unknown

4

0.8

17.5

0.25

8.4

4.7

28

βLd

Notes

Refs.

-

-

IPA (2014)

Reaction force pilein test D

8.8

Filled-in concrete

IPA (2014)*

Notes: Bored: Bored Pile Method; Gyro: Gyropress Method assisted with rotary cutting (Gyro Method);
WJ: Press-in Method assisted with water jetting (WJ Method)

test A,B,C

test D,E

test F

test G

test H

test I

made groundtest J

Fig. 1Site Profiles- 127 -

Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

2.4. Test Condition
Loading tests were carried out according to one-kH 0 

1
E 0
0.3

(5)

directional loading tests in the step loading method

BH 

B


(6)

standardized by the “Method of horizontal loading tests ofpiles (Japan Geotechnical Society (JGS 1831))”. The
following are the ones that require attention, such as thosedifferent from the above test method and those that havespecial field conditions.
Test F was used as the reaction pile for test D and was
13 m away from the center of the pile in test D. As for the
direction of deformation, test D was in the influence rangeof about 5 times the foundation width. This was ignored

E 0  2800N
where,
E: Elastic modulus of steel
I: Moment of inertia of area for foundation
kH: Coefficient of horizontal subgrade reaction
BH: Equivalent loading width of foundation
E0: Elastic modulus of ground
Po: horizontal load,

g: Ground deformation, andp: Deformation at loading point

since the pile width in test D was small compared with thefoundation width in test F.

Note that in addition to the pile stiffness at each

In test H, the soil about 300 mm around the pile was
improved by permanent grout after the pile installation(Fujiwara et al. 2015). Though there might be little effect(7)

sectional stiffness, that of steel members to protect
monitoring instruments were added.

on the horizontal resistance, the result of test H was used
as a reference. In addition, horizontal loading test was

2.5.2.

Yield Deformation of Ground

For the estimation of elastic range on the horizontal

performed after vertical loading test.
Finally, in test I, the soil inside the steel tubular pile
was excavated after the pile installation, and the void wasfilled with concrete from the pile toe for a length about 5
times the pile diameter. It was also ignored, judging thatthe situation inside the steel tubular pile would not affectbehavior of piles, there are different methods, including
one to estimate from the point at which residual
displacement abruptly increases in step loading, one to use
a point at which displacement increases while keeping a
constant load, or one that uses reference displacement in
the Weibull distribution curve (Eq.8).

the horizontal resistance.

Though the first method is often used fromperformance required for lateral resistance, there are

2.5. Analysis Method
2.5.1.

Coefficient of Horizontal Subgrade Reaction
Assuming the ground is simulated by elastic

springs, and that the coefficient of horizontal subgrade
reaction is constant in the depth direction, horizontal
displacement at the ground surface and that at the loading
point are given by Eqs. (1) and (2), respectively. Grounddeformation modulus was estimated by the N-value as in
Eq. (7) to evaluate all the tests by the same method, notusing the results of the hole horizontal loading tests.
1 h
(1)
g 
Po
2EI  3

repeated loading. Though the estimated value of thesecond method is presumed to correspond to the creep
limit of the ground, all the records of the change over time
were not left. As for the third method, according toOkahara et al. (1989) in which the characteristic value ofground displacement gs obtained from the Weibull
distribution curve is regarded as the yield displacement of
the ground gy, comparing with the point at which theresidual displacement abruptly increases in step loading.
Therefore the same assumption was adopted, though gs

1   h   1 2 P(2)and gy are different in a precise sense and clear points
which residual displacement abruptly increases in step

kH B
4EI

(3)

loading could not be found around the displacement gs.
Note that in fitting the result of the load test with the

3

p 

drawbacks such as dependency on the number of steps in 4

3EI  3ok H  k H 0 B H 0.3 4


3

(4)

load control by the Weibull distribution curve, the result at
the small displacement amount are emphasized too much.

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Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

Therefore, displacement at each step was weighted among
the results of step loading tests so that the residual sum ofsquares became minimum (Nakatani et al. 2009a).

Po 1 e
Pou

 g



 D 

 gs m
D 


test

(8)

Gy ro

where,

exp.

Weibull
Curve

B
D
E
J
A

ref.

None

Pou: Ultimate horizontal bearing capacitygy: Yield deformation of ground (=gs)
gs: Characteristic value of ground deformation, and(a) Gyro-press

m: Deformation index
3. RESULTS AND ESTIMATION
3.1. Load-Displacement Curves
Weibull distribution curve is described by the three

test
WJ

G
H
I
A

variables of deformation index m, maximum load Pou andcharacteristic value of ground deformation gs. When all
the variables were changed in data fitting, calculated yield

exp.

ref.

Weibull
Curve
None

None

displacement became remarkably large. Consequently,
final fitting was carried out fixing the index m = 1, which(b) Water-jet

is often used in the approximation of the Weibull

P – δg Curve (m=1) for single pileFig. 2

distribution curve (e.g. Okahara et al. 1989, Nakatani et al.
2009b).
Fig. 2 shows load-deformation results and Weibull
distribution curves at each loading test for eachconstruction method. The results with the application of
the Weibull distribution curve are shown in solid lines,
while ones installed by Bored Pile Method are shown by
dotted lines. In addition, since in the data fitting of test G,(

the maximum ground displacements in the loading tests
were smaller than 1.1 times gs, it was judged that theestimation accuracy was low and was excluded from the) test H
improved by permanent grout

evaluations. Note that as described later, the cases for
single piles were used here in order to exclude the effectof foundation width for multi number of piles (tests C and

Relationship between δgy and D

Fig. 3F in this paper. Termed pile groups hereinafter). It may beseen that the load-displacement curves are relatively

Table 2.

consistent when m = 1 is assumed, and that loosening of

Statistics of δgy / D

means

num

M

SD

CV

GM

GSD

Gyro

4

6.0%

1.3%

0.21

5.9%

0.22

yield

WJ*

2

2.1%

1.3%

0.64

1.8%

0.70

displacement gy and the pile diameter D is shown in Fig.
3 The result of test H was shown for reference because of(test I)

1

1.1%

-

-

1.1%

-

Notes: M:mean, SD: standard deviation, CV:coefficient of variation,

permanent grout. A broad correlation between gy and D is

GM:geometric mean, GSD:geometric standard deviation

noticeable in the Gyro method. Statistical values gy*: including test H in which ground was improved by permanent grout

ground due to construction is not identified especially in
the initial displacement.
Next,

the

relationshipbetweenthe- 129 -

Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

normalized by D are listed in Table 2 for each construction
method. Though there were few test data, geometricmeans for single pile was 5.9 % for the Gyro Method,while it was 1.1 or 1.8 % for the WJ Method. The results
suggest that compared with the average values of 4.1 –4.5 % for steel tubular piles installed by other construction
methods (Fig. 4), the value of Gyro Method shows a little
larger, whereas that of WJ Method shows somewhat
smaller. However, since the yield displacement 1.1% islarger than the most frequent value in Fig. 4 and thereference value 1.0% (JRA, 2017), it is too early to declarethat WJ Method has a clear influence on the yieldδgy / D [%]Fig. 4

displacement.

Relative frequency distribution of δgy / D for steel
tubular piles (Okahara et al. 1989)

3.2. Back Calculated coefficient of Subgrade Reaction
The relationship between normalized coefficient ofhorizontal subgrade reaction kH and the normalized
horizontal displacement at the ground surface is shown in
Fig. 5. Here, kH calculated backward from thedisplacement at the loading point with the assumption that

Bored Pile
Method ( )ground is represented by elastic springs was normalized
by the design kH, which is given as Eq. (4), while thehorizontal displacement at the ground surface wasnormalized by the pile diameter.

(a) Gyro-press

In this section, only the cases of single piles were also
used to exclude the effects of foundation width. Calculated
backward kH where the ground displacement normalized

improved bypermanent grout( )by the pile diameter is 1 % is larger than the design kH for
all the cases constructed by the Gyro Method (Fig. 5a).
On the other hand, for cases constructed by the WJ method,
the average of kH where δg/D = 1% are regarded fairly
Bored Pile
Method ( )consistent with the design kH, but the variation of themseem large (Fig. 5b).
3.3. Effect of Foundation Width
Next, the effect of foundation width was checked,
using the test data with different pile diameters or different(b) Water-jet
Fig. 5

Relationship between normalized kH and δg /B

Fig. 6

Image diagram of interference by pile groups

number of piles at the same test location (tests B to F).
Note the data used here are all constructed by the Gyro
Method. Note that in test F, the displacement at the loading
point was not measured, so kH was calculated backwardfrom the horizontal displacement at the ground surface.
It is known that in a continuous pile foundation,
horizontal

resistant

force

is

reducedbymutualinterference among piles. In the case of a group of piles as- 130 -

Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

displacement at the ground surface is about 15 mm (e.g.
ASPP 2007).
Shimomura and Suzuki (2016) have reported that forlarge diameter pile foundations, the calculated backward
kH tends to be smaller than the design kH . It is inferred forsteel tubular pile foundations with small stiffness as in thisstudy that the same thing applies.
Consequently, for steel tubular pile continuous walls,
it is considered proper that the reference displacement
used to calculate ground reaction force is not one(a) arranged by δg/B

proportional to the pile diameter but that a constant value
should be used.
4. CONCLUSIONS
From the results of the study, the following have beenchecked:

Load-displacement curves of the WJ and the Gyro
Method are consistent with that obtained from the
Weibull distribution curve for a displacement index m= 1.0.
The average yield displacement normalized by the pile
diameter with the Gyro Method is consistent with the(b) arranged by δgaverage values of 4.1 – 4.5 % for steel tubular piles

Fig. 7 Effect of foundation width on normalized kH

installed by other construction methods, and that with
the WJ Method gives smaller value than the average ofshown in Fig. 6, it is expected that the load shared by thecenter pile would be smallest because of the interferences

other construction methods.


The coefficient of horizontal subgrade reaction

from both sides. However, there were little apparent

calculated backward from the displacement at thedifferences between the center pile and the side pile whenloading point showed somewhat larger value than thethe distribution of bending moment in the depth direction

design value when the reference displacement was set

were looked at. Consequently, it was judged here that theat 1 % of the pile diameter in the case of the Gyro

steel tubular piles were behaving as an integrated body.

method. On the other hand, for cases constructed by

As in the previous section, Fig. 7a shows therelationshipbetween thecalculated

backward

the WJ method, the average of measured kH is regardedkH

fairly consistent with designed kH, but the variation of

normalized by the design kH and δg normalized by thefoundation width B, and Fig. 7b shows the relationshipthem seem large.
In the case of group piles, δg - kH curves were better

between the normalized kH and δg. It may be seen in Fig.

fitted than δg / B - kH curves. The calculated backward

7a that the normalized kH of pile group is smaller than thatkH approximately coincides with the design kH whenof single pile when δg is normalized by pile diameter, andthe horizontal displacement at the ground surface isthe difference between them is large. On the other hand, it

about 15 mm.

is seen from Fig. 7b that the relationship between kH andδg of the group pile is relatively the same with that of thesingle pile when δg is evaluated by themselves.

5. ACKNOWLEDGEMENTS
The results of loading tests used in the analysis were

Furthermore, the calculated backward kH approximately

provided by the collaborative research between Nippon

coincides with the design kH when the horizontal

Steel and Sumitomo Metal and GIKEN (Matsui et al.

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Proceedings of the First International Conference on Press-in Engineering 2018, Kochi2009) and the collaborative research between Cambridge

Nakatani, S., Shirato, M., Kono, T., Iochi, H. andUniversity and GIKEN, and from Gikenseko Co. Ltd. The

Kirikoshi, T. 2009b. Geotechnical Criterion forauthors are indebted to their collaboration.

Elastic Limit of Horizontally-Loaded Pile, Technical
Note of PWRI, No. 4151. (in Japanese)

REFERENCES
Association of Steel Pipe Pile (ASPP). 2007. Design

Okahara, M., Takagi, S., Nakatani, S., Taguchi, K. andManual of Cantilever Steel Sheet Pile Retaining

Resistance Characteristics of Piles with the Use ofWalls. (in Japanese)

Loading Test Data, Technical Note of PWRI, No.

Sakamoto, A., 1989. Investigation on Lateral

Fujiwara, M., Tanigawa, J., Tsuchiya, M. and Murata, K.

2721. (in Japanese)

2015. Countermeasures against Installation of Long

THE PORTS & HARBOURS ASSOCIATION OF

Steel Pipe Piles and Quality Assurance of Bearing

JAPAN (PHAJ). 2007. Technical Standards andCapacity by Load Tests, Proceedings of 70th JSCE

Commentaries for Port and Harbour Facilities in

Annual Meeting, Section IV, No. 015, pp. 29-30. (inJAPAN, Last Volume. (in Japanese)

Japanese)

Technical Committee on Vibration Hammer Method. 2015.

International Press-in Association (IPA). 2014. Design

Design and Construction Manual for Vibration

and Construction Manual of Steel Tubular Pile Earth
Retaining Walls by Gyropress Method (Rotary

Hammer Method. (in Japanese)
Shepley, P. and Bolton, MD. 2014. Water Supply to a

cutting Press-in). (in Japanese)

Geotechnical Centrifuge for Pile Jetting in Sand,

International Press-in Association (IPA). 2015. Design

Physical Modelling in Geotechnics - Proceedings ofand Construction Manual of the Press-in Method. (inthe 8th International Conference on PhysicalJapanese)

Modelling in Geotechnics, pp. 281-287.

Japan Geothechnical Society (JGS). 2010. Standards of

Shimomura, S. and Suzuki, Y. 2016. Coefficient of LateralJapanese Geotechnical Society for Lateral Load Tests

Ground Reaction Force of Single Pile in Sandyof Piles. (in Japanese)

Ground Based on the Results of Lateral Loading

Japan Road Association (JRA). 2017. Specifications ofTests of Wide Range Pile Diameters, Architectural

Highway Bridges and Explanation, IV: Substructures.

Institute of Japan, Technical Report, Vol. 22, pp. 919-

(in Japanese)

924. (in Japanese)

Matsui, N., Suzuki, T., Hirata, S. and Kimura, Y., 2009.

Shimomura, S. and Suzuki, Y. 2017. Coefficient of Lateral

Bearing Capacity Performance of Pressed-in SteelGround Reaction Force of Single Pile in Clay Ground

Tubular Piles by Rotary Cutting (Gyropress Method);

Based on the Results of Lateral Loading Tests ofPart 2: Lateral bearing capacity, Proceedings 64th

Wide Range Pile Diameters, Architectural Institute

JSCE Annual Meeting, III-130, pp. 259-260 (inof Japan, Technical Report, Vol. 23, pp. 93-98. (inJapanese).

Japanese)

Nakatani, S., Shirato, M. and Yokomaku, K. 2009a. Study

Uto, K., Fuyuki, M. and Sakurai, M. 1982. Compilationon Axial Deformation Characteristics of Pile,

Method of the Results of Pile Loading Tests, The

Technical note of PWRI, No. 4139. (in Japanese)

Foundation Engineering & Equipment, Vol. 10, No.
9, pp. 21-31. (in Japanese)- 132 -