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

Case Study of Underwater Press-in Method of Steel Sheet Piles under Restricted
Headroom beneath a Railroad Bridge
Minoru ARAI
Head of Hinachi Dam Branch Office, Kizu Integrated Dam Control and Management Office, Japan Water Agency, Nabari
City, Japan
Email: minoru_arai@water.go.jp

Shunji SUGIO
Director, Numata Integrated Dam Control and Management Office, Japan Water Agency, Numata City, Japan

Katsuyuki MURAYAMA
East Japan Railway Company, Takasaki City, Japan

Hiroki KUNITOMI
Totetsu Kogyo Co., Ltd, Takasaki City, Japan

Yasumasa KIMURA
Construction Solutions Department, GIKEN LTD., Tokyo, Japan

ABSTRACTThe Musashi Canal is a facility which diverts water from the Tone River to the Arakawa River. In 40 years of use since
its completion, the canal had various challenges. To tackle those challenges, the Musashi Canal Reconstruction Project
was implemented from 2010 till 2015. There were, however, extremely severe construction conditions in the projectsite. Firstly, the construction work needed to be implemented without any interruption of serving water since it was avery crucial water resource for the Tokyo Metropolitan area. Secondly, it was never allowed to affect the railway serviceof JR-Takasaki Line which is an artery of transportation for the metropolitan area and crossing over the canal. To
implement the reconstruction under these constraints, we developed a new steel sheet pile press-in technology. In detail,there were four major improvements on a sheet pile press-in machine and development of a special steel sheet pilewhich has two specific functions. Sheet piling has already been used at a lot of construction sites. However, there was alimit on its use at sites where only narrow work space in a vertical direction is allowed. With the use of this newtechnology, this disadvantage has been overcome successfully and it is expected that the technology would be further
improved and developed through future rehabilitation and renewal projects.
Key words: canal reconstruction, press-in machine, sheet pile, mechanical joint, lateral interlocking

1. Project outline
The Musashi Canal with the total length of 14.5 km isyear to about 13 million people living in 18 wards and 18

a concrete lining canal which flows through Gyoda City

Saitama Prefecture, which supports society and economy

and Konosu City in Saitama Prefecture and diverts waterof the metropolitan area as a crucial lifeline.

cities of Tokyo Metropolis and in 20 cities and 8 towns offrom the Tone River to the Arakawa River as shown in

However, the Musashi Canal which had been in use

Fig. 1 and 2. It was constructed in March, 1967, to solve

for about 40 years was facing the following challenges.

the problem of water shortage in the metropolitan area

Recovering its capacity of conveying water which

during the period of rapid economic growth. The Musashi

had decreased by 30% due to wide range land

Canal is still supplying municipal water throughout thesubsidence and deterioration of canal itself- 533 -

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

Strengthening earthquake resistance assuming amanner with serving water on another side. Also, thefuture large scale earthquake

double lane can reduce life cycle costs by extending life

Strengthening drainage of inland flood water inof the facility.

consideration with urbanization along the canal etc.
2. Background of developing the new technology ofpress-in sheet piles under waterThis project was implemented under the very severe
constraint that the facility needed to be totallyreconstructed with the conveyance of domestic water forthe metropolitan area continuously, which was thefunction of the existing facility. In particular, a hard workat the point of intersection of JR-Takasaki Line and theMusashi Canal (about 100m long) was foreseen from its
planning phase.
Two

stage

diversionwas

adoptedforthereconstruction work of the 14.5 km-long canal, whichenables construction of both sides of the canal in turn.
Firstly, all bridges and roads which would hinder thereconstruction work were diverted.

Then, by placing

steel sheet piles into the canal center lengthwise, removalof the existing canal and construction of the new canalFig. 1 Location of the Musashi Canal

became possible using one side as a dried working area
while conveying municipal water on the other side asshown in Fig. 3.

Fig. 2 Location of construction site

To tackle these challenges, the “Musashi Canal
Reconstruction Project” had been implemented for seven

Fig. 3 Process of reconstruction by two stage diversion

years from 2009 till 2015. The reconstructing work wastoconverttheexisting

trapezoidal

canal

with

However, only the Mida bridge crossing over the

150mm-thick plain concrete lining into a double-lane

Musashi Canal was not able to be removed since it wasrectangular canal which was made of reinforced concrete.

located on JR-Takasaki Line which is a major artery

The Musashi canal had been serving as an importantconnecting Hokuriku, Shinshu and North-Kanto regions

lifeline for the metropolitan area and was not allowed towith the metropolitan area. More than 300 trains gointerrupt its service for a long period. Consequently,

across the bridge at 5 to 10-minute intervals. Given

major repairing works could not have been carried out

social and economic importance of the railway service, iteven if the canal would have been severely damaged.

was necessary to implement the reconstruction work with

For this reason, the existing canal was drasticallythe bridge remaining and with the service secured.

restructured into the double lane canal which enabled to

On the other hand, the canal of reinforced concrete

check and repair one side of the canal in a planned

double flume could not be constructed in this place- 534 -

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

because of physical interference by the abutments of the

3.1. Development of the main body of a press-in

Mida Bridge. Bypassing the canal to other places was
also unrealistic due to densely built-up residential areasmachine for use under extremely low clearance
The press-in machine for use under the extremely

nearby the construction site. Consequently, the design for

low clearance (hereinafter referred to as “Press-in

this section was changed to be of the double siphon.

machine”) is a system which enables all of hoisting,

Under these circumstances, steel sheet piles neededpitching and press-in operations concerning steel sheet

to be placed at the center of 20m wide canal in flowing

piles within the clearance limit of 1.0m (between the top

water under the railway bridge as shown in Fig. 4.

of the steel sheet pile and the bottom of the bridge) as

Specific conditions are shown below, which wereshown in Fig. 5 and 6. This Press-in machine

unprecedentedly severe ones even in the world. In orderincorporates four features improved from conventional

to handle these challenges, it was inevitable to developpress-in machines.

new innovative technology on placing sheet piles.
<Conditions>i)First priority for the safety and stability of railway
transportationii)

The extremely limited clearance with 1.5m height
between the bottom of bridge and the surface of thewater with the flowrate of 20m3/sec and the velocity
of as high as 2.0m/seciii) Underwater press-in of steel sheet piles with only
1.0m clearance between the head of sheet piles andthe bottom of bridge
Fig. 5 New method

Fig. 6 Process of press-in operation by new method

Fig. 4 Construction conditionsi)

Lower machine body・The mechanism of conventional press-in method isthat a press-in machine of 2,520mm in height placedon the top of settled steel sheet piles clamping 3 or 4

3. Development of new technology
The newly developed technologies of this time canpoints of web of sheet piles from which the machine

be summarized as following two subjects.

can receive reaction force. A sheet pile is broughti)

Development of the main body of a press-in

into the machine by a crane and pressed into themachine for use under extremely low clearance

ground chucking with a settled sheet pile.

ii)

Development of special steel sheet piles and a・hoisting device for them

In a conventional way, at least 3m added clearance
is required taking into account the height ofmachine and the space for rotation of crane which isused for serving a new sheet pile from above. In
addition, sheet piles can be pressed in only from- 535 -

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

・higher place than settled sheet pile heads.
・In the case of the conventional press-in machine,

By overcoming these technical challenges, the newsteel sheet piles were pitched from above using apress-in machine with a lower body was developed.

crane.

The height of this machine including the press-in

・

Pitching of a steel sheet pile from the side of thestroke was low enough to be set in the clearance ofpress-in machine became possible by developing a

1.0m and it could place a steel sheet pile from below

pitching equipment named open chuck as shown in

the top of settled sheet piles.

Fig. 9 and 10.

ii)

Horizontally movable function

・The conventional

machine・

As a result, it became possible to pitch a pile longer
than the height of clearance above the machineis equipped with

self-moving function, but it needs to raise itself

using underwater space.

above the top of sheet piles beforehand by clamping
webs of settled sheet piles.
・

Developing a new type of clamps which grip jointsof steel sheet piles made possible horizontal
self-movement as shown in Fig. 7 without raisingitself.

Fig. 9 Pitching a steel sheet pileFig. 7 Horizontal movement of press-in machine by new
methodiii) Press-down function
・The conventional press-in machine could not grasp
steel sheet piles under the water surface, since itclamped the piles directly by a stroke jack.

・

By pushing down the press-down rail using thestroke jack, press-in action of steel sheet piles underFig. 10

Open chuck

the water surface with the moving jack clamping
These developments made more space available andthem became possible as shown in Fig. 8.

enabled a longer steel sheet pile to be placed into
underwater. Furthermore, improvement of construction
speed was attained by reducing the number of verticaljointing parts of the steel sheet piles.
3.2. Development of special steel sheet pile
Adjacent steel sheet piles are normally connected
Fig. 8Mechanism of press-in a steel sheet pile in new methodwith each other by inserting an interlocking part of one
pile vertically into an interlocking of the other pile.

iv) Pitching a steel sheet pile

However, the special steel sheet pile was developed to be- 536 -

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

fitted from lateral direction by horizontal feed joints in
S-shape as shown in Fig. 11, so that the function of the
new press-in machine to pitch steel sheet piles in thehorizontal direction (named “open chuck function”) canbe made use of.
Additionally, it was necessary to increase thenumber of vertical joints for the work under limited
clearance since only a short sheet pile was available andit needed to be added one by one for the required length.
Furthermore, at the construction site, underwater welding
in a rapid stream running at 2.0m/sec was required. To
cope

with

these

difficulties,

together

with

the

Fig. 12development of the new press-in machine, the special

Development of special steel sheet pile(#2 mechanical vertical joint)

steel sheet pile employing a mechanical vertical joint wasdeveloped, which makes usable the new machine’s

As a supplement, bending strength of the special

function of placing a sheet pile down into water and also

steel sheet pile and tensile strength of the vertical joint

makes underwater vertical jointing possible. As a result

were confirmed to be satisfactory by the full-scaleof this development, no more welding operation in

bending strength test. Furthermore, to secure required

rapidly flowing water is required and overall safety andwater cut-off performance, water-swelling rubber was

performance on construction were greatly improved.

employed for connecting parts of each steel sheet pile as

Moreover, the employed joint has the structure ofa leakage countermeasure and water-swelling sealing

one-touch joint and water cut-off performance is secured

material was applied to section parts as shown in Fig13.

as shown in Fig. 12.

Fig. 13Development of special steel sheet pile3.3. Development of auxiliary equipment for placingi) Special steel sheet pile hoisting device
Dedicated rails for hoisting a sheet pile and aplacing device were also developed in parallel so thatspecial steel sheet piles could be placed safely, andunderwater placing could be performed easily on thecanal under the bridge. This is a system to serve a steel
sheet pile by moving the hoist in the front/rear andleft/right directions along the two rails laid between
support pillars placed into the canal and the foot of thebridge.

Fig. 11Development of special steel sheet pile(#1 horizontal feed joint)- 537 -

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

water flows into the Arakawa River, then is taken at
Asaka Water Purification Plant (right bank side: Tokyo
Metropolis) and Okubo Water Purification Plant (leftbank side: Saitama Prefecture). Once an oil leakage
accident happens, it immediately leads to interrupting
intake at both of the water purification plants, so strict
countermeasures against oil leakage are required.
At the site of construction work, all externally
exposed parts of hydraulic hoses related to the press-in
machine were completely cured and waterproof structure
was employed for the main body of the press-in machine
including hydraulic moving parts.
4. Troubles and solutions during construction
4.1. Press-in capacity of the new machine for use
under extremely low clearance
During pressing a sheet pile in by the newly
developed machine, it was observed that larger reduction
Photo 1.

of pressing power than that of the conventional press-in

Special steel sheet pile hoisting device

machine.
ii)

Openable catching arm

The new machine clamps settled steel sheet piles at

The Musashi Canal has a rapid stream with the flow

different points from those clamped by the conventional

velocity of 2.0m/sec and there was some concern that apress-in machine. Comparing the normal vector of bothsteel sheet pile would be tilted by the stream when being

clamped reaction base and press-in point, it was foundplaced, and that it might not be placed exactly vertically.

that there is some gap. This gap caused some loss of

To avoid this, it was decided to newly develop an

press-in power by giving the lateral external force to theopenable catching arm to prevent a tilt and sway of steel

machine and tilting steel sheet pile on which the press-in

sheet piles. Closing the catching arm enables a steel sheet

machine sat as shown in Fig. 15. Given this lesson

piles to be placed correctly preventing any tilt and swaylearned, it should be noted that loss of press-in

as shown in Fig. 14.

performance needs to be taken into account when a work
plan is made.

Fig. 14

Catching Arm

Fig. 15iii) Oil leakage countermeasures

Loss of press-in performance of press-in machine

4.2. Securing construction quality of underwater

The Musashi Canal is a facility to supply domestic
water to 13million residents of Tokyo Metropolis andjointed parts
As already mentioned, a special steel sheet pile was

Saitama prefecture. Right after running down the canal,

jointed with an adjacent steel sheet pile by horizontal- 538 -

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

feed joints first, then it was lowered into and jointed
under water with the steel sheet pile settled previously byvertical mechanical joints. The integrated sheet pile wasfurther pressed into the ground. For securing theconstruction quality, it was confirmed by an operator of
the press-in machine by checking a monitor image which
was taken with an underwater camera and presented on alaptop PC.
Although confirmation work was under a very
severe condition as well as construction, like high flow
velocity of 2.0m/sec and constant turbidity which

Photo 2.

Space for workes

allowed only 30cm visibility, joints could be sufficiently
confirmed by attaching LED lights to the underwater
camera and protecting its front lens by an acrylic board.

5. Summary
In this construction work, in order to overcome
unprecedentedly difficult conditions of construction in theworld, we tackled development of a comprehensive new

4.3. Breakup of lining concrete
The special steel sheet pile needed to be pressed intechnology including press-in a steel sheet pile below

after breaking up lining concrete (plain, t=250mm) of thewater surface and horizontal movement of the press-in

bottom floor of the existing canal. For this process, it wasmachine, which was technically based on the press-inplanned to break lining concrete in advance using

method with the use of the Silent Piler.

another specific steel sheet pile whose edge wasAs a result of this, the conventional concept ofprocessed and reinforced in the shape of cutting edge injointing steel sheet piles could be changed with the use ofparallel with the use of a water jet. Then, the special steel

the newly developed horizontal feed joint which can be

sheet pile could be pressed in.

fitted in the lateral direction, and also with the use of

Actual construction work could be carried out
almost as planned, but there were cases which took moremechanical vertical joint which can be joined in water
quickly.

press-in time than planned. Judging from the situations

Using this newly developed technology, construction

visually confirmed after closing and drainage of the canal,

works that had to be given up in the past due to low

the probable cause of this could be considered that someclearance could become possible and this technology

of concrete pieces destroyed in advance had dropped into

would be used at a lot of construction sites. Furthermore,holes made by the water jet and caused extra placing forthe application to “renewal work of urban infrastructure

press-in work of steel sheet piles.

which has complicated three dimensional shape” and“indoor retaining work” can be considered. It is expected

4.4. Securing space for operation
Placing work had to be done in a stream with flowthat through recognition by many people further

velocity of 2m/sec and also in extremely low clearance ofwill make them more useful ones.

improvements will be made on these technologies, which

1.5m from the water surface to the bottom of the bridge.

It is anticipated that this paper would be a good

To secure the space for workers to support placing piles,

opportunity for this technology to be broadly recognizedboat-shaped pontoons were deployed at both sides of theby many people.

press-in machine as shown in Photo 2, which was
equipped with an openable working passage to connect
the work spaces on both sides and allow smooth

References
Hasegawa, S., Takada, M. and Takata, K. 2014. Press-in

movement between each side.

Method of Steel Sheet Piler for Use under the
Extremely Low Clearance beneath the JR Railroad- 539 -

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

Bridge, Proceedings of 69th Annual meeting, Japan
Society of Civil Engineers, VI-447, pp. 893-894.
Kunitomi, H. and Takata, K. 2015. Case Study on
Press-in Machine of Steel Sheet Piles under the
Extremely Low Clearance on the Canal beneath theRailroad Bridge, Proceedings of 70th Annual
meeting, Japan Society of Civil Engineers, VI-606,
pp. 1211-1212.
Japan Construction Method and Machinery ResearchInstitute. 2012. Report on the Full-scale Bending
Strength Test of the Steel Sheet Pile Wall with
Employing both mechanical Vertical Joint andHorizontal Feed Joint (Comparison of the Strengthwith Conventional Steel Sheet Pile).

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