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

The Countermeasure for Press-in Method on Lengthy SPSPs and theConfirmation of the Bearing Capacity Obtained by Pile Loading Test
Le Anh DUNG
Department of Civil Engineering, Nishimatsu Construction, Tokyo, Japan
Email: leanhdung@nishimatsu.co.jp

Motohiro FUJIWARA
Kanto Civil Engineering Branch, Nishimatsu Construction, Tokyo, Japan

Mitsuhiro TSUCHIYA
Department of Civil Engineering, Nishimatsu Construction, Tokyo, Japan

Teijiro SAITO
Department of Civil Engineering, Nishimatsu Construction, Tokyo, Japan

ABSTRACT

A Steel pile sheet pile (SPSP) foundation on a viaduct construction site was designed and constructed using the press-in
method combined with inner excavation. After driving the pile, the press-in method combined with inner excavation was
not able to drive the piles into the ground to the required depth, so the press-in with water jetting method was adopted
after considering environmental impact, economy, and work schedule. With the press-in with water jetting method, thepile was driven to the required penetration depth while water was pumped under high pressure through pipes internallyattached to the pile. The press-in with water jetting method was selected as a piling method for the steel pipe sheet pilefoundation which is adjacent to a river, a highway, and houses in a confined space. There has been no recommended
bearing capacity formula for press-in with water jetting method in Japanese design specifications for highway bridges, so
the information of the vertical resistance characteristics (end-bearing capacity, skin friction) and lateral resistancecharacteristics (modulus of horizontal subgrade reaction) of the foundation was determined by a loading test to obtain theproperties of foundation after changing the pile driving method. Using chemical grouting to increase the ultimate bearing
capacity is also discussed. According to the results of vertical loading test and horizontal loading test after ground
improvement, the ultimate bearing capacity was confirmed to be greater than the designed value for Level 2 earthquake.
The stress in the piles was confirmed to be smaller than the allowable value both for Level 1 and Level 2 earthquake.
The Steel pipe sheet pile foundation using the press-in with water jetting method combined with the grouting method
had full structural abilities for Pier structures.
Key words: press-in with water jetting, pile loading test, frictional resistance, grouting

1. Outline of the project

1.2. Background and objectives of the project
The foundation of piers includes Sheet pile soil cement

1.1. Place
The project involves the construction of approximately afoundation(φ1200 L=10.0m~42.5m) and Steel pipe sheet

1.2 km long viaduct substructure (47 piers and 2

pile (SPSP) foundation (φ800 L=15.5m~51.0m, theabutments) of Metropolitan Inter-City Expressway incombination with temporary cofferdam). In this report,Okegawa city (See Fig. 1, No.2 viaduct substructure

the construction of Steel pipe sheet pile foundation isconstruction).

carried out (See Fig. 2).

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No.1 Viaduct site
(Steel superstructure)

No.3 Viaduct site
(Steel superstructure)

No.2 Viaduct site
(PC superstructure)

No.5 Viaduct site
(Steel superstructure)

No.4 Viaduct site
(PC superstructure)

No.2 Viaduct Substructure construction(Jan, 2012 ~ Sep, 2014)

Okegawacity

Fig. 1The layout of the construction site

PD18PD18PU20Fig. 2The layout of Steel pipe sheet pile foundations

The SPSPs were installed using the press-in method

to the 51.0m length of piles (PU20 Pier (See Fig. 3)), thecombined with inner excavation (press-in forces 800kN,press-in method combined with inner excavation was notinner excavation with tip enlarged foot protection

able to drive SPSP into the ground to the required depthmethod) in the original design. The numbers and theduring the construction of the first long SPSP. This islengths of SPSPs are shown in Table 1. A total of 4 SPSP

because the friction between piles and clay soil increased

foundations using the 15.5m length of SPSPs (See Fig. 2)

with the penetration of piles. In the first countermeasure,

were installed completely by using the press-in method

the hydraulic vibratory pile hammer (vibration force

combined with inner excavation. However, with regards

473kN) and the electric vibratory pile hammer (vibrationforce 568kN) were used to penetrate the pile into theTable 1.

Number and length of SPSPs

bearing layer. However, they did not work well.
The press-in with water jetting method was adopted
instead. There has been no recommended bearing
capacity formula for press-in with water jetting method
in Japanese design specifications for highway bridges.
Therefore, the confirmation of the bearing capacity by
pile loading test was conducted.
2. Site condition
2.1. Site condition
The construction site is adjacent to a residential area
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Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

Kanto
loam
Sand(s)Sand(s)Gravel(g)Clay(c)Gravel(g)Sand(s)Clay(c)Sand(s)Sand(s)Clay(c)Sand(s)Gravel(g)Clay(c)Sand(s)Fig. 3

Soil boring log and SPSP foundation of PD18 Pier

Fig. 4

Soil boring log and SPSP foundation of PU20 PierEntering
the river

Fig. 5 Press-in with water jetting method

andaprecision

machinetoolplant,

Fig. 6

therefore

environmentally friendly methods such as those with less

3. Press-in piling3.1. Layout

noise and less vibration must be applied. In addition, theavailable time allocated to the main road was limited,

The retention basin

A photo of typical press-in with water jetting method isshown in Fig. 5.

and it was difficult to modify the schedule. For the above
reasons, the press-in with water jetting method using

3.2. Wastewater treatmentpress-in forces 2600 kN of a press-in machine was

The force applied using the Press-in machine wasadopted to drive pile to the required depth instead of2600 kN. A total of 4 water jetting machines (AT330ES

changing to other methods like caisson foundation or pileV) with maximum recharge of 900 l/min capacity werefoundation.

used to supply water which was taken from the adjacentriver.
As for the water treatment, wastewater during

2.2. Ground condition
Soil description and Standard Penetration Test (SPT)

construction was transferred to a retention basin

are shown in Fig. 3, and Fig. 4. The penetration depth ofapproximately 200 m away from the site with appropriate

PSPSs is planned to locate mainly in the stiff sand layer

authority without a mechanical process. In the retention

where N value is larger than 50.

basin, a sandbag weir was constructed to prevent waste- 67 -

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

soil from entering the river and allow the supernatant toflow to the river when the water level is higher than theweir height (See Fig. 6).
3.3. Piling process
With the press-in with water jetting method, the pile isdriven to the required penetration depth while the wateris pumped under high pressure through pipes internallyattached to the pile. At the same time, water flow reducesskin friction of pile and reduces interlock resistance by
washing out soil inside the interlock. There has been norecommended bearing capacity formula for press-in withwater jetting method in Japanese design specifications forhighway bridges, so the information of the verticalresistance characteristics (end-bearing capacity, skinFig. 7

The Test flowfriction) and lateral resistance characteristics (modulus ofhorizontal subgrade reaction) of the foundation wasdetermined by a loading test to obtain the properties offoundation after changing the pile driving method.
The test flow is shown in Fig. 7. After confirming thebearing capacity of the test pile, the press-in method wasconducted without chemical grouting. Otherwise, thechemical grouting will be used to increase the ultimate
bearing capacity. After grouting, the loading test will beused for proof of bearing capacity working on the pile.
The driving of PU20 Pier with sheet pile 51.0 m longusing the press-in with water jetting was used todetermine the test flow.
4. Results
4.1. The press-in with water jetting
Sheet piles with lengths from 47.5 m to 51.0 m of 4
Piers were successfully driven using the press-in withwater jetting.
During construction, the noise level did not exceed
75dB consistent with the noise regulation standards,
improved

environmentalconditions.

Becausethesupernatant was allowed to flow into the river, the levelof suspended solids (SS) was measured 2 times per day
duringconstructionofSPSPs

todetermine

Fig. 8press-intheThe view of site during and after thecharacteristics of the municipal wastewater. The resultwith inner excavation. There are no differences between

shows that SS did not exceed the wastewater effluent

two press-in methods of driving time so there was nolimit of 180 mg/L.

negative impact on the use duration of the main road.

The driving of the SPSPs was from 0.5 to 0.7 pile/dayin the initial planning with the press-in method combined

Fig. 8 shows the construction conditions during
driving and after driving the pile.

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4.2. Pile loading test (Before ground improvement)
Strain gauges (32 points of 16 cross-sections into 2

resistance. The curing period (14 days) was determined indirections), displacement gauges (installed in the pile tip)

original schedule. In addition, the SPSPs wall did notand multi-layer inclinometer (10 points in 10 crossprevent the dissipation of excess porewater pressuresections) were installed to measure the displacement ofbecause the interlocked joints are typically permeable,test pile during driving to the required depth (See Fig. 9).

which allows leakage through these joints (TheThe capacity of the test equipment was 8000 kN. Theinterlocked joint of the SPSPs filled by mortar after thetest equipment consists of 2 load beams (1700 mm×450loading test). The results of the vertical loading test aremm), 4 load transfer beams (864 mm×750 mm), 8

shown in Fig. 11. When the load test was 2400 kN, thereaction piles (See Fig. 10). The location of reaction pilesend-bearing capacity value was 1767 kN which wasand test pile of loading test was carried out with respectsimilar to the value of the method of installing piles by

to Japanese design specifications for highway bridges.

inner excavation combined with final strike method

accordance with [JGS 1811-2002] and the limit of theA vertical loading test on the pile was conducted 14(1764 kN) calculated by the formula of Japanese design

days after driving pile by using the press-in with water

specifications for highway bridges. In addition, thejetting method in order to ensure the recovery of frictionalend-bearing capacity, skin friction and ultimate bearing
capacity of pile using inner excavation combined with thepressure feed of cement milk method in the original

Fig. 10 Vertical pile loading test
LoadＰP (kN)
(kN)
軸力0500

1000

1500

2000

2500

30000

深度 (ｍ)

Depth below pile head (m)1020304050
800kN

1600kN

2000kN

2400kN

2800kN

3200kN

60Fig. 9Fig. 11 Relationship between load test
and depth below pile head

Outline of the gauges- 69 図－軸力深度分布図

3500

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

design was 3544 kN, 4275 kN and 7819 kN, respectivelyevaluate the effective bound of grouting (See Table 2). In(See Table 3, calculated by the formula of Japanesethe same sand layer, the N value of Br-No.3 was less thandesign specifications for highway bridges).

other borings results. There was no difference between N

Design skin friction was calculated for the condition tovalue of borings in the loam, clay soil layer. As a result,

ensure that the foundation failure will not occur in agrout is injected at the points which are 0.3 m outside theLevel 2 earthquake. The test skin friction capacity (632cofferdam (See Fig. 13). Therefore, grouting was setkN) was less than design skin friction (2470 kN ).

outside the cofferdam and injected from pile head to toe

The load test was 3200 kN although the plannedlevel based on the structural design of the cofferdam.

maximum test load was 8000 kN (See Fig. 11). So theTable 2.

chemical grouting method with permanent grout material

Boring data

was used to increase frictional resistance of piles.
4.3. Ground improvement
4.3.1. Grouting method
A process of injecting grout under pressure into theinterface between the exterior of the shaft and thesurrounding soil after completion of driving SPSPs wasplanned to increase the skin friction capacity.
Comparingwithimprovement

suchotherasmethods

chemicalofgroundgrouting

method(dual-tube double-packer method) and jet grouting
method, the dual-tube method has no problem with deep
ground improvement and able to obtain the strength ofpermanent grout material. In addition, the dual-tube
method was more economical. As a result, the dual-tube
method was adopted.

Fig. 13Ground Improvement

4.3.3. Grouting
After completion of driving SPSPs, grouting was taken

Fig. 12 Extra Boring position

4.3.2. Design
A total of 4 extra borings were conducted at the nearing

for 4 tabular foundations.

sheet pile to evaluate the property construction range
limit of grouting in advance (See Fig. 12). Three borings

4.3.3.1. Boring
Because grout is injected at the points which are 0.3 m

were outside the cofferdam with the distance 0.3 m

outside the cofferdam, borehole will be made 0.15m(Br-No.3), 0.5 m (Br-No.2), 2.5 m (Br-No.1) respectively

outside the foundation similar to a number of the pile by

and another one was inside with the distance 0.3 musing 2 rotary packer drill machines (See Fig. 14).

(Br-No.4).
Based on the data from the original boring and extra
boring, the soil strata and N value were determined to4.3.3.2. Injecting
The injection of permanent grout material was- 70 -Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

Table 3.

Fig. 14

Results of loading test

Boring apparatus

Strain(µ)
ひずみ量 ε0200(μ )80040060010001200

1400800kN

1600kN

2400kN

3200kN

4000kN

5600kN

6400kN

7200kN

8000kN

8800kN

Fig. 16

Relationship between strain and depth020

深度 (杭頭-ｍ)Fig. 15

Depth below pile head (m)10Injecting apparatus

conducted using 8 machines of grout injection pump. In
order to control pressure balancing on the pile, SPSPs

30

4050

foundation was divided into 8 parts (3 piles/part), and thegrout was injected at a staggered arrangement to ensurethat the adjacent points are not injected at the same time60(See Fig. 15).
Eight grout injection pumps were used at the same

4800kN

time at 8 parts to avoid gradual injection pressure andprevent the escape of grout.

below pile head
図－ひずみ量深度分布図

4.3.4. Pile loading test (After ground improvement)

method combined with inner excavation.

4.3.4.1. Vertical loading test
After 28 days of grouting, vertical loading test was

4.3.4.2. Horizontal loading test

conducted to confirm the bearing capacity of test pile. In

After excavation and leveling work inside theFig. 16 when the load test was 8800 kN, thecofferdam, a horizontal loading test was conducted. The

displacement at the pile toe was less than 10% of the pilehorizontal loading test was made by pushing three piles

toe diameter. So the second-limit-resistance was greater

togetherthan load test (8800 kN) and its original design value

displacement which was planned to be larger than 15 mm(7819 kN).

(See Fig. 17).

duringloading

tomeasurehorizontal

The skin friction capacity after completion of grouting

After obtaining the load-deflection data during loading

was similar to its value of original design using press-in

test, the modulus of horizontal subgrade reaction was- 71 -Proceedings of the First International Conference on Press-in Engineering 2018, Kochi

Fig. 17

Horizontal loading test setting

was determined based on the steel pipe sheet pile
Modulus of horizontal subgrade reaction (kN/ m2)

foundation in order to solve the problem in construction.
The loading test was conducted to clarify the effects ofthis method and to confirm the bearing capacity before
and after taking countermeasures using the chemical
grouting method. The main conclusions are outlined
below.
(1) After using the press-in with water jetting method, thereduction of skin friction was confirmed by using verticalloading test.
(2) The skin friction capacity after completion ofgrouting was similar to its value of original design using
the press-in method combined with inner excavation.
(3) The coefficient of horizontal subgrade reaction
Horizontal deflection (mm)Fig. 18

obtained by horizontal loading test after grouting was

Relationship between modulus of horizontal

similar to its value of original design. It was the same

subgrade reaction and horizontal deflectionlevel in comparison with the original ground.

calculated as shown in Fig. 18. The coefficient of(4) According to the results of vertical loading test andhorizontal subgrade reaction obtained by horizontal

horizontal loading test after ground improvement, theloading test after grouting was similar to its value of

ultimate bearing capacity was confirmed to be greater

original design. The ultimate bearing capacity wasthan the design value for Level 2 earthquake. The stressconfirmed to be greater than the design value for Level 2in the piles was confirmed to be smaller than theearthquake. The stress in the piles was confirmed to beallowable value both for Level 1 and Level 2 earthquake.

smaller than the allowable value both for Level 1 andLevel 2 earthquake.
According to the results of vertical loading test andReferences
Japan roadhorizontal loading test after ground improvement, theassociation.

2012.

Japanesedesignspecifications for highway bridges.

Steel pipe sheet pile foundation using the press-in withJapanese geotechnical society. 2004. Method for static

water jetting method combined with grouting method had

axial compressive load test of single Piles [JGS

full structural abilities for Pier structures.

1811-2002].
Japanese geotechnical society. 2010. Method for lateral

5. Conclusion
In this report, the press-in with water jetting method- 72 -load test [JGS 1831-2010].