International Press-in Association

Volume 7, Issue 4 December 2022

www.press-in.org

I NSIDE T HIS I SSUE
1. Messages (P1)
New Director

Message

From the New Director
Shinji Taenaka

2. Special Contribution (P2)
3. Interview Reports (P15)
4. Reports (P21)
・Board Meeting
・From Regional Office
5. Event Report (P25)
・Singapore Seminar・Vietnam Workshop
6. Young Members (P29)
7. Event Diary (P30)
8. Corporate Members (P31)
9. Editorial Remarks (P33)

EDITORIAL BOARD
Nor Azizi Bin Yusoff
Michael Doubrovsky
Ramin Motamed
Chun Fai Leung
Pastsakorn Kitiyodom
Anh Tuan Vu
Mark Albert H. Zarco
Shinji Taenaka
Adnan Anwar Malik
Chen Wang
Tsunenobu Nozaki
Hongjuan He

General Manager, Head of Infrastructure & Construction Engineering Dep.
Nippon Steel Corporation
I am honored to join the international Press-in Association (IPA)
as a new director and the first one from the steel industry. I am
working for Nippon Steel Corporation, which is one of the large
steel makers to supply steel tubular piles, sheet piles and so on.
This article introduces a few distinctive steel products in Japan.
Hat-Type sheet piles1 are a unique type of steel sheet pile,
supplied since 2005. Before that, U-shaped sheet piles with aneffective width of less than 600 mm were mainly used. In sheet
pile wall built up of U-shapes, slipping of the interlocks at the central bending axis of
the pile wall can lead to the reduction of the wall stiffness and strength. To overcome
the inherent weakness of U-shape, Hat-Type sheet piles have been developed. This
hat-shaped cross-section has interlocks at the edge of the wall where an individual
pile can make up the wall height, resulting in full cross-section performance (i.e.,
noreduction). The effective width of 900 mm in Hat-Type makes it more rigid than Ushape, leading to easy installation with less deformation. Nowadays, Hat-Type has
been more standard in Japan and started to be used in Asian countries such asSingapore.
Another unique steel product is a steel tubular pile with protrusions (ribs) on theouter or inner surface2. This pile is made by pipe forming using the special steel plateon which the high pressure of the hot-roll process embosses equidistant, parallel
shear keys ridges. Utilizing this steel pile with outside ribs, the steel pipe soil cement
pile method (i.e., composite pile) has been developed so far in which cement milk is
injected into the original ground and mixed and stirred while the steel pile is installedat the same time. The pile has a large friction capacity due to adhesion between thesurrounding soils, the soil-cement and the steel tubular pile with ribs.
In the future, technical fields of Press-in Technology are widely expanding beyond not
only geotechnical engineering but also mechanical engineering, material engineering
as above and other fields. As for the steel industry, we hope to contribute to thedevelopment of Press-in Technology, by providing high-quality steel products as wellas the development of new products and advanced applications.

◆ A brief CV of Dr. Shinji Taenaka

Dr. Shinji Taenaka is head of Infrastructure & Construction Engineering Dept. of
Nippon Steel Corporation and has more than 20 year-experience with a wide rangeof research on steel pipe piles and steel sheet piles from both geotechnical andstructural engineering. He has contributed to several successful developments ofpiling methods, foundation systems and disaster countermeasures using steel pipe
piles & sheet piles as well as novel steel products such as Hat-Type sheet piles.
1 See Photo 3 on IPA News Letter Vol. 7, Issue 3
2 See Fig. 5 on IPA News Letter Vol. 7, Issue 3

1Volume 7, Issue 4

December 2022

Special Contribution

Steel Pipe Piles, Tubular Sheet Piles, Steel Sheet Piles
Confronting Natural Disasters
Toshiharu Hirose
ManagerJapanese Technical Association for Steel Pipe Piles and Sheet Piles (JASPP)The Japanese archipelago is an arcuate archipelago located off the eastern coast of the Eurasian Continent and in thenorthwestern coast of the Pacific Ocean, where the oceanic plates of the Pacific and the Philippine Sea plates subductbeneath the continental plates of the Eurasian and the North American plates. For this reason, trench-shaped submarine
depressions called ocean trenches and ocean basins (troughs) exist off the south and east coasts of the Japanesearchipelago, which frequently generates plate boundary earthquakes in these areas. In addition, cracks (faults) are formedin the land area of the surface of the plate as the continental plate is pushed by the oceanic plate, where intra-continental
plate earthquakes, also called fault earthquakes or active fault earthquakes, often occur.
Surrounded by the Sea of Japan, the Sea of Okhotsk, the Pacific Ocean, and the East China Sea, the Japanese archipelago
has a mild climate with four distinct seasons. On the other hand, it suffers wind and flood damage quite frequently, as
steep mountainous areas account for 70% of the country, and besides, it often has heavy rain caused by mobile lowpressure systems and typhoons. Furthermore, climate change due to global warming in recent years, so-called guerrilla
rainfalls (localized heavy rain), and localized heavy rain caused by the occurrence of linear rainfall belts have caused largescale landslides and floods many times.

1. Steel pipe piles, tubular sheet piles and steel sheet piles in earthquake disasters(1) 1964 Niigata Earthquake (M7.5): Major damage to a modern city due to liquefaction
At 13:01 on June 16th, 1964, this earthquake occurred with the epicenter about 40km south of Awashima Island in Niigata
Prefecture. A large-scale liquefaction phenomenon occurred throughout Niigata City, which caused extensive damage tosocial infrastructure facilities such as rivers, ports, airports, railways, and general buildings. This earthquake captured
worldwide attention as it was the first case where a modern city experienced large-scale liquefaction.
In Niigata City, reinforced concrete buildings suffered the most damage. More than 300 out of 1,500 buildings in the citywere damaged, but 189 buildings sank or slanted without any damage to their superstructures. At the "Prefectural
Kawagishi-cho Apartments" located on the left bank of the Shinano River, 3 out of 8 buildings were greatly tilted due tothe liquefaction phenomenon, and one of them was almost overturned. It was also the time when color television began
to spread, and the shocking images made the liquefaction damage known to the general public.
After the earthquake, a large number of investigators were dispatched from related organizations in order to investigate
the damage situation to the buildings and in order to consider restoration methods as well. Since there was no fatal
damage to the superstructures of the damaged buildings, there were few cases of demolishing and rebuilding evenheavily sloping buildings. Most of the buildings were restored by raising the foundations in some way.
The Niigata Telecommunications Department Office Building (Photo 1.1) suffered damage with a maximum subsidenceof 530 mm and a maximum tilt of 1/40 to 1/50, but no harmful cracks were found in the structure.
In this case of building restoration, in addition to the following reasons: (1) there was no damage that might hinder its
continued use, (2) it was not desired to spend the cost of newly rebuilding it, (3) similar re-damage should be avoided,
considering the construction cost and construction period, a method was adopted in which “as a structure to support thebuilding, steel pipe piles were to be pressed into the foundations of the columns to raise the building horizontally”. For
the restoration, while using the second floor and above of the building, steel pipe piles with a length of 1.0m were added,
and the number of steel pipe piles corresponding to the column load were pressed in with a jack. Concrete was placedon the top of the pile, which was used as a jack fulcrum when raising the building (Fig. 1.1).

2

Volume 7, Issue 4

Photo1.1 Niigata Telecommunications Dept.
Office Building1)

December 2022

Fig.1.1 Detailed Drawing of Leveling1)(2) 1968 Tokachi-oki Earthquake (M7.9): Standards were revised due to the damage to RC (Reinforced concrete) buildings
At 9:48 on May 16, 1968, the earthquake occurred with the epicenter off the east coast of Aomori Prefecture (far off
Sanriku). The damage occurred from Tohoku Region to Hokkaido centering on Aomori Prefecture, with a 3m high tsunami
hitting Erimo Cape in Hokkaido and a 3 to 5m high tsunami hitting Sanriku. There were geo-disasters that caused 52
casualties. 673 buildings were completely destroyed, 3,004 were partially destroyed, and 15,697 were partially damaged.
Especially in Aomori Prefecture, reinforced concrete public buildings which had been built after 1960, such as Misawa
Commercial High School (Photo 1.2), Hachinohe Higashi High School, Hachinohe Technical College, and Mutsu City Hall,
were severely damaged. This led to the revision of the "Building Standard Law Enforcement Order", and also the"Standard for Structural Calculation of Reinforced Concrete Structures (Architectural Institute of Japan)" in 1971.

(3)1978 Miyagiken-Oki Earthquake (M7.4): The first earthquake to hit a large city with a population of over 500,000.
At 5:14 p.m. on June 12, 1978, this earthquake occurred with the epicenter (seismic intensity 5) approximately 100 km
off the east coast of Sendai City, Miyagi Prefecture. Liquefaction caused damage to the lifelines such as gas and watersupply on flat land along the coast, and conspicuous damage was caused to the first floors of buildings in industrial
complexes located on reclaimed land. Landslides and collapses occurred at the boundary between the natural groundand embankments in new residential areas built on hilly areas. This turned out to be a heavy damage where 4,385 houses
were completely or partially destroyed, and 86,010 houses were partially damaged. It was regarded as a typical urban
earthquake that a large city with a population of more than 500,000 people encountered for the first time.
In this earthquake, excavation surveys were actively carried out on the foundation piles of building structures, and it wasclarified that (1) PC piles (prestressed concrete piles), especially AC piles (high-strength concrete piles), were significantly
damaged, (2) in the case of the buildings which had damaged piles, the ground was not extremely soft, but slightly soft.
On the other hand, in the hilly residential area near the center of Sendai city built after 1960, many landslides occurredon the embankment. It was reported, however, that there happened no damage from the Tohoku-Pacific Ocean
Earthquake that occurred later in March 2011, in the area where the collapsed land had been turned into a green space
and a concrete leaning retaining wall had been constructed with a steel pipe pile foundation that also had served as anearth retaining wall, as a restoration method. (Photo 1.3).

Photo 1.2 Damaged building of Misawa
Commercial High School2)

Photo 1.3 Affected area in Sendai City3)3Volume 7, Issue 4

December 2022

(4)1995 Hyogo-ken Nanbu Earthquake (M7.3): Steel pipe pile foundation demonstrated excellent seismic performance
At 5:46 on January 17, 1995, the earthquake occurred at the bottom of the Akashi Strait, with the epicenter at a depth of
16 km. It was the first large-scale earthquake with a seismic intensity of 7 recorded in Japan, which caused a major disasterthat killed more than 6,000 people, mainly in the city of Kobe. It caused extensive damage to the infrastructure facilities
such as roads, railways and ports, buildings such as ordinary houses, offices and condominiums, and the lifelines such as
electricity, water and gas. Turning out to be an unprecedented earthquake disaster, it was later called the Great HanshinAwaji Earthquake.
Steel foundations and steel structures such as steel pipe piles, tubular sheet piles, and steel sheet piles had been used inmany coastal facilities and structures including landfills. These damage conditions had something in common, and mostof them were judged to be the effects of lateral displacement due to liquefaction of the surface ground and the backfill
soil, sliding failure of the ground due to reduction in effective stress, etc. In addition, there were cases in which steel pipe
piles used for piers were damaged because of the deterioration of the bearing strength of the pile material caused by the
progress of corrosion due to insufficient anti-corrosion treatment. However, it was confirmed that many steel foundations
and steel structures were generally sound, which turned out to show the characteristics of "steel" such as high strengthand excellent deformation performance.
1) Damage to steel pipe piles, tubular sheet piles, and steel sheet piles in revetments, quay wall structures, etc.
A visual inspection was carried out by ship from the sea side for the seawalls, quay walls, piers, pier foundations, etc.
which had used steel pipe piles, tubular sheet piles, and steel sheet piles in the coastal reclaimed land of Maya Wharf,eastern construction area, Ashiyahama, Nishinomiyahama, and Kobe Port Island, and Rokko Island as the target areas.
Tables 1.1 and 1.2 show the damage status of structures and the damage rank of structures. About 70% of the 23 surveyed
structures had no damage to the steel pipe piles (damage rank: A, B).
Table 1.1 Damage to structures 4)

Damge situation
Structures

A

Seawall

2

Quay

1

Jetty quay

6

1

Pier Foundation

3

1

Locks/water gates
Facility foundation,
etc.
Total

2
14

B

C

D

Total
2

1

2

4

11
4
2

2

4

2

2

3

23

Table1.2 Damage ranks of structures
DamageDamage situation
rank
A
The superstructure, facilities, and foundation piles are all sound and functionally unaffected.
There is damage to the superstructure and facilities (functional impediment), but theBfoundation piles are sound.
There is damage to the superstructure and facilities (functional impediment), and some ofC
the foundation piles need to be repaired and reinforced.
D
Damage to the superstructure, facilities, and foundation piles (functional impediment)
Note: Produced based on the information given in Table 1.14Volume 7, Issue 4

Photo 1.4 West side of Maya Wharf6)

December 2022

Fig. 1.2 Foundation of the west side of Maya Wharf7)a) Damage to revetments and quay walls
At Port Island and Rokko Island, gravity caisson quays suffered severe damage, while pier structures suffered minor
damage. “The Maya Wharf No. 1 Jetty West Quay (Photo 1.4)” was a seismic revetment with a horizontal design seismic
intensity of 0.25. In the vicinity of the base of this jetty, a counterweight fill was placed on the sea side of the existing
steel plate cell foundation, and further, a double-layer structure was adopted with a new quay-wall of steel pipe sheet
piles with battered piles installed (Fig. 1.2). In addition, the tip of the pier had a very solid double-foundation quay witha steel plate cell on the land side and a caisson on the sea side, and although there were some cracks in the concrete due
to uneven subsidence at the connection part between the horizontal pier and the caisson, there was no functional
problem after the disaster.
On the other hand, the quay on the east side of Maya Wharf was a steel plate cell type quay that partially used OD400(400mm in outer diameter) and OD500 steel pipe piles in the apron part, but the steel plate cells tilted toward the sea
and buckling occurred in the steel pipe pile heads, and the function of the quay was hindered. The cause was attributed
to the fact that the excessive horizontal force acted on the piles in the apron as the steel plate cells tilted forward due tothe excessive flow pressure and the vertical and horizontal seismic motion because of the liquefaction.

b) Damage to the pier type wharf
Of the 11 surveys of pier type quay walls, 4 were functionally impaired. The characteristics of the damage common tothese were as follows.
1, The caisson-type revetment on the land side was displaced toward the sea from the existing revetment line, and therevetment was inclined toward the sea.
2, Pier structures have two types; A structure type composed of vertical piles, and a type of vertical and better piles,
and buckling was observed in steel pipe piles.
3, The top of the pier was slanted toward the land (in some quays, toward the sea).
At a certain quay, damage (one case) was observed in which one of the piles was broken in the direction perpendicular
to the pile axis. The main cause was attributed to the fact that the thickness of the steel pipe plate was reduced due tocorrosion because of insufficient anti-corrosion protection on the aging pier. Whereas no damage was observed in the
structures for which new anti-corrosion methods had been adopted such as heavy anti-corrosion coating and FRP cover,and sufficient anti-corrosion measures.
c) Facility foundations (walkway behind the quay, foundations of ancillary facilities such as land-side cranes, etc.) andother damage situations.
At the Higashi-Kobe ferry wharf, the caisson quay was displaced approximately 1-2m toward the sea from the existing
line, and the ground between the caisson quay and the footpath foundation collapsed about 2-3m. Steel pipe piles of
OD400 were used for the footpath foundation, but the steel pipe piles and the footing were completely separated, leaving
the steel pipe piles exposed. The main cause was attributed to the fact that the pile head was only embedded about 100
mm into the footing (no pile head rebar).

5Volume 7, Issue 4

December 2022d) Actual cases of recovery
Shinko Pier No. 4 (-12m quay) (Photo 1.5), located at the base of theShin-Kobe Ohashi Bridge leading to Port Island, had been used as aninternational passenger berth. Regarding the restoration method, as
there were constraints because it was in the water area in front of theslip (between jetties), and the shed was close behind, a method was
adopted in which steel pipe sheet piles were to be placed in front of theexisting caissons, and underwater concrete was to be filled between
them.
2) Damage to steel pipe piles in building structures

Photo 1.5 Shinko No.4 Pier（-12m quay）8)

A visual inspection was conducted on 45 building structures using steel pipe piles in Kobe Port Island, Rokko Island,
Fukaehama-cho, and Naruohama-cho. Table 1.3 shows the damage to the foundations of building structures.
Table 1.3 Damage to the foundation of building structures 5)
Locationconditions
Port Island
Rokko Island

InlandCoastal area
InlandCoastal area

Foundation damage
No

Yes

16
0
16
2

0
8
40
0

Sub-total
16
8
16
2

Total
24
18

Fukaehama-cho
Inland2
1
3
3
Naruohama-cho
Total
36
9
45
45
Classification of damage degree
Foundations were damaged: For those with exposed pile heads, the pile heads were damaged such as buckling or
deformation, or the footings were damaged or displaced. If the pile heads were not exposed, the footings were obviously
damaged or displaced.
No foundation damage: No damage or displacement on piles or footings.
a) Cause of foundation damage
There was no damage to the foundation in 36 out of 45 investigations (80%). Of the 9 cases where damage was confirmed,
8 cases were warehouses adjacent to the container berth in Port Island, and it was presumed that the foundation frame
had been displaced due to the lateral displacement of the ground accompanying the berth damage. The other was abuilding located inland, where the top of the pile was exposed and a slight tilt was observed, but no damage to thesuperstructure was confirmed. Of the 36 foundations without damage, 4 had exposed steel pipe piles, but no damage
such as buckling or deformation was observed. It was concluded that the reason why the two structures (bothwarehouses) in the Rokko Island coastal area had no damage to the foundations was that they were located relatively
inland and had little impact from the damage to the berth.
b) Damage to the superstructure
Of the 45 cases surveyed, 13 cases had damage to the main body (beams, columns, walls), and there were 11 cases where
the main body was sound but incidental facilities (stairs, connecting corridors, elevators, etc.) were damaged. There were
21 cases where both the main body and incidental facilities were sound and the damage was limited to subsidence of thesurrounding ground (damage to underground pipes, damage to parking lots and sidewalks).
Of the 13 cases where the main body was damaged, 5 were condominiums and housing complexes, and the other 8 were
warehouses adjacent to the container berth. The damage to the condominiums and housing complexes located in theinland area was mainly X-shaped cracks generated on the walls. The damage to the warehouse adjacent to the berth wascaused by the movement of the foundation frame due to lateral displacement of the ground, and tilting and deformationof the entire building.

6

Volume 7, Issue 4

December 2022

3) Survey results of the damage to steel pipe piles, tubular sheet piles, and steel sheet piles (summary)
A visual inspection after the Hyogo-ken Nanbu Earthquake (Great Hanshin-Awaji Earthquake) revealed that, except forsome cases, most of the independent steel pipe pile foundations such as pier type quays and building foundations were
found to be sound, regardless of subsidence of the surrounding ground or damage to the superstructure.
The common point of the revetments, quay structures, and building structures with foundation deformation was thatthey were all located near the reclaimed revetments. Although there was no direct pile body damage due to the seismic
motion, it was speculated that, in the coastal area, the caisson quay walls and revetments moved significantly due to thefluid pressure accompanying the lateral displacement of the ground, which caused deformation and tilting of the steel
pipe piles of the pier and the foundations of the factory warehouses located nearby.
(5) 2004 Niigata Prefecture Chuetsu Earthquake (M6.8): Recorded seismic intensity 7 for the second time in recorded
history
At 17:56 on October 23, 2004, it occurred with the epicenter 13 km deepin Kawaguchi-cho, Kitauonuma-gun, Niigata Prefecture (currently
Nagaoka City). It was an inland earthquake with a maximum seismic
intensity of 7, which was the second time in recorded history after the
Hyogo-ken Nanbu Earthquake. There were 19 aftershocks with a seismic
intensity of 5 lower or more by the end of December of this year.
Due to the rainfall caused by the typhoon that had passed three days
before the earthquake, landslides occurred one after another on theslopes of the hills. In the former Yamakoshi Village, houses collapsed withearth and sand (Photo 1.6), and there was damage caused by the outflow
of irrigation water from Nishikigoi farming ponds making use of terraced
rice fields. In mountainous tributaries, collapsed sediment clogged river
channels, forming natural dams that cut off traffic routes, leaving many
communities isolated.

Photo 1.6 Landslide at Former Yamakoshi
Village9)

There is a case of restoration of a railroad bridge damaged by this earthquake by pressing-in a steel sheet pile continuous
wall around the damaged pier and thereby carrying out the repair and the seismic reinforcement at the same time. By
filling the interior of the steel sheet pile continuous wall with concrete and integrating it with the existing pier, the shear
strength and deformation performance of the piers were improved. By installing steel sheet piles (also used as atemporary cofferdam) with a compact press-in machine, the need for large-scale temporary construction work was
eliminated and thus the construction period was shortened.
(6) 2011 off the Pacific Coast of Tohoku Earthquake (M9.0): An unprecedented catastrophe caused by a giant tsunami
At 14:46 on March 11, 2011, it occurred with the epicenter off Sanriku, about 70 km east of Sendai City. The huge
earthquake that occurred at the boundary between the North American plate and the Pacific plate recorded a magnitudeof 9, the largest in Japan's history, and a violent shaking with a maximum seismic intensity of 7 lasted for more than 2
minutes. About 30 minutes after the earthquake, a gigantic tsunami with a wave height of 10 m or more and a maximum
run-up height of 40 m swept the Pacific coast of the Tohoku region, causing devastating damage to the coastal areas of
Hokkaido, Tohoku and Kanto (Photo 1.7, Photo 1.8). As of March 2021, 15,899 people died and 2,526 people were missing
due to this earthquake, 90% of whom were victims of the huge tsunami. It was called the Great East Japan Earthquake
because it was an unprecedented earthquake disaster that spread from Hokkaido to Kanto.

Photo 1.7 A huge tsunami that hit Miyako
city, Iwate Pref 10)

Photo 1.8 Seawall damage at Sanriku
Town, Ofunato city 10)7Volume 7, Issue 4

December 2022

Liquefaction damage was also serious in landfills in the coastal areas and on the soft ground along the rivers. In Urayasu
City, Chiba Prefecture, for instance, a large amount of groundwater containing sand erupted, causing manholes to riseand buildings to tilt. The lifelines were also severely damaged. Furthermore, at the Tokyo Electric Power Company's
Fukushima Daiichi Nuclear Power Plant, the electrical system of the reactor was damaged by flooding caused by the hugetsunami, and the core cooling system stopped. As a result, the cooling water inside the reactor pressure vessel evaporated,
and as the water level dropped, the hydrogen generated by the chemical reaction between the exposed fuel rods and thesteam leaked into the reactor building and exploded, causing the ceiling and walls to be destroyed. After all, evacuationof residents still continues in some areas because of the scattering of highly concentrated radioactive materials causedby the venting that was carried out to lower the pressure inside the reactor containment vessel. It was an accident thatraised a big problem to society regarding the safety of nuclear power plants.
After the earthquake, our association conducted surveys on steel foundations and steel structures such as steel pipe piles,
tubular sheet piles, and steel sheet piles in various fields such as roads, railways, ports, and construction. The result was
published as a report (October 2011)11) and a second report (December 2012)12).

Photo 1.9 Bearing deformation11)

Photo 1.10 Damage to Kamaishi Bay
mouth breakwater10)1) Damage to structures using steel pipe piles, tubular sheet piles, and steel sheet piles
The damage to structures using steel pipe piles, tubular sheet piles, and steel sheet piles in the Great East Japan
Earthquake was as follows.
a) Road and railway field
No major deformation was found in the main bodies of the bridge foundations, except for the bridges whose
superstructure and substructure were washed away by the tsunami. As for the bridges that were washed away, it was
assumed that the damage to the foundations themselves due to the seismic motion was minor. As damage to thefoundation bodies due to the earthquake motion, although some deformation of the bearings and cracks on theembankment slopes at the abutments were confirmed, no major deformation was confirmed in the foundation bodies,and they were found almost sound (Photo 1.9).
b) Construction field
In many areas, the tsunami caused enormous damage such as the outflow, overturning, collapse, and inclination ofbuildings. In Onagawa Town, the tsunami also caused pile foundation structures to fall over (Table 1.4). On the other hand,no damage was confirmed in the structural frame of the building using the steel pipe pile foundation.
c) Port field
The post-earthquake tsunami caused major damage to breakwaters and seawalls in many areas of the Tohoku region,
including collapse, etc. (Photo 1.10), but damage to quay walls and seawalls was limited.

8Volume 7, Issue 4

December 2022

Table 1.4 Damage to overturned buildings(pile foundation structures) in Onagawa Town12)
DamagedOnagawa Police Boxbuildings
2 story RC building

Ejima Kyosai Hall

Hotel building

Seafood processing
warehouse

3 story steel building RC 4F
RC 2F(partially 4F)
Long side x short side x
Long side x short side x
StructureLong side x short side x
height = 10m x 4.8m x 10m Long side x short side x height = 5.6m x 5.6m x
scaleheight = 20m x 8.8m x 10m
Tower ratio: short side = height = 16m x 8.4m x 12m 14.5m
Tower ratio: short side =2.08 long side = 1.00
Tower ratio: short side = Tower ratio: short side =1.14 long side = 0.50
1.43 long side = 0.75
2.59 long side = 2.59
・ Tumble north on the ・ It seems that the ・ It seems that it was ・ It looks like it fell overspot
tsunami was received swept
west(uprush after being hit by a・It seems that PHC piles from the short side of the direction) more than 70m tsunami (push wave) inof OD300 were used for building.
from its original position. the direction of the shortthe foundation piles.
・ From the tsunami ・It seems that PHC piles side.
・All piles broke near the footage taken in the of OD300 were used for ・ Although there were
pile headvicinity, it seems that the the foundation piles.
some traces of having
・ The extracted part is building did not topple ・Most of the piles broke been connected with
exposed while being over until the first wave at the original position of stakes on the bottom ofconnected to the footing (pushing wave) of the the building.
the footing,・There are collision marks large tsunami reached the ・ Only one pile was (1) No traces of rebar
on the roof and walls
third floor of the building. dragged as far as the cages, etc., can be
・It seems that PHC piles position
where
the confirmed at the joints ofof OD250 were used for building was washed away the foundation piles.
Damagethe foundation piles.
and broke.
(2) There are no traces ofsituation
・ At the bottom of the ・At the original position, foundation
piles
exposed footing, the pile four piles remained about embedded in footings.
head joint rebar filling 2m pulled out.
(3) Footing thickness is
concrete, and one pile thatvery small.
was pulled out remain.
Therefore, it seems that
・The length of the pulled
the footing and the pile
pile was 6.0m (broken atwere not connected.
the originally welded
spot?)
・Except for this one stake,the stakes appear to havebeen left at their original
positions on the building.

DamagephotosReprinted from Note 1*

Reprinted from Note 1*

Reprinted from Note 2**

Note 1* Yahoo! JAPAN: Great East Japan Earthquake Photo Preservation Project
Note 2** TETSU (Satoshi Nakayama): Tama Watch, May 6, 2011, Tsunami Damage, Onagawa Town, Miyagi Prefecture2) Steel foundations and steel structures that contributed to restoration and reconstruction
For the recovery and reconstruction of the Tohoku Region Pacific Ocean Earthquake (Great East Japan Earthquake), steel
pipe piles, tubular sheet piles, and steel sheet piles were used in a lot of cases because they had excellent strength,
deformation performance, quality, and workability for disaster-resistant city development and infrastructurereconstruction. Here introduced are some application cases of steel pipe piles, tubular sheet piles, and steel sheet piles
which made a particularly large contribution.
9

Volume 7, Issue 4

December 2022a) Application case of steel pipe piles and steel sheet piles [Ishinomaki disaster recovery work: construction period from
October 2011 to March 2014][Damage situation]
Due to crustal movement and liquefaction caused by the earthquake, the entire fishing port area settled by approximately
1.3m (average value), and various facilities such as piers and wharves were destroyed or damaged by flooding. The
designed water deep -7m quay (extension 270m) and -6m quay (extension 700m) settled about 1.15m in the entire area,
and the head of the steel sheet pile in front of the revetment was pushed out to the sea side with a maximum of 46 cm
in and out of the sheet pile normal line. Also, the apron collapsed and was constantly submerged.
[Recovery method]
While restoring the original shape, a design was made for the purpose of raising the height of the subsidence, andregarding the steel sheet piles that caused the normal deviation, new sheet piles were installed slightly forward theexisting sheet piles (Photo 1.11). A new steel pipe pile was also installed for the H-shaped steel that had collapsed in theexisting apron. A steel sheet pile was driven at 1.7m forward the normal line to the old revetment, Steel piles with 600
mm in diameter and 12 to 17 m in length were driven into the apron area, and the front steel sheet piles were tied with
about 13m long tie rods to serve as an anchor (Fig. 1.3).

Fig. 1.3 Designed water depth - 7m quay
wall restoration standard cross section13)

Photo 1.11 New Installation of steel sheet piles ofdesigned water depth - 7m quay13)b) Application case of tubular sheet piles [Ishinomaki Port Higashihama Coast Seawall Restoration Work][Damage situation]
An upright concrete embankment with TP (Tokyo peil) + 3.3 to 3.5m, which was built in the 1960s and 1970s, settled byapproximately 1m due to the earthquake, and besides, the front of the seawall was scoured by the tsunami surge andcollapsed during the undertow, resulting in two levee breaches.
[Recovery method]
A new seawall was decided to be constructed as a disaster recovery project, and a plan of an upright embankment with
an embankment structure of continuous self-supporting tubular sheet piles with a height of TP + 7.2m was adopted (Fig.
1.4). A normal coastal embankment required a slope on the sea side in order to ensure the specified strength without
affecting the harbor road behind it, so a relatively expensive construction cost and a long construction period were issues.
For this reason, a continuous wall made of self-supporting tubular sheet piles was adopted as an upright embankmenton the sea side which also would be able to suppress lateral flow during liquefaction (Photo 1.12).

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Volume 7, Issue 4

Fig. 1.4 Ishinomaki Port Higashihama coastal seawall
standard cross section14)

December 2022

Photo 1.12 Installation of tubular sheet piles on the
Higashihama coastal embankment of Ishinomaki Port14)

2. Steel pipe piles, tubular sheet piles, and steel sheet piles in the case of typhoon and heavy rain disasters(1) September 2015 heavy rains in the Kanto and Tohoku regions: Steel sheet piles contributed to the restoration of levee
breaches in the first-class rivers
Typhoon No. 18, which occurred on September 7, 2015, went north over the southern Sea of Japan. After making landfall
on the Chita Peninsula of Aichi Prefecture at around 10:00 on September 9, it advanced to the Sea of Japan and became
an extratropical cyclone at 21:00 on the same day. After that, due to the influence of the moist air of Typhoon No. 17
flowing from the south into the low pressure that had changed from the typhoon, heavy rains spread over a wide areafrom western Japan to northern Japan, and the Kanto and Tohoku regions experienced record rainfall. In particular, from
September 9th to 10th, Nikko City, Tochigi Prefecture, recorded 551 mm of rainfall in 24 hours, which was the highest
since observation began in 1975, and other observation points (16 points) also broke observation records for the 24-hour
precipitation. Under these circumstances, heavy rain special warnings were issued by the morning of the 10th in Tochigi
and Ibaraki prefectures. The Kinugawa River overtopped and overflowed in Ibaraki Prefecture, which is located in the
midstream region. In the early afternoon, the embankment on the left bank of the Kinugawa River in Misaka-cho, Joso
City, collapsed for approximately 200m. Eventually, a wide area in Joso City sandwiched between the Kinugawa River and
the Kokaigawa River was submerged, the city hall main building, which had been completed the previous year, wasflooded, and more than 5,000 houses were completely or partially destroyed, causing extensive damage due to long-term
flooding (Photo 2.1). The levee breach of the Kinugawa River was the first case since it had occurred in Tochigi Prefecture
in August 1949, and the levee breach of a state-managed river in the Kanto region was the first since it had occurred in
the Kokaigawa River in August 1986.
The restoration work for the collapsed levee was carried out for two weeks as an emergency restoration by means of arough cofferdam and steel sheet pile double cofferdam (Fig. 2.1). After that, in January 2016, during the non-flood season,
the main restoration work was started. After removing the rough cofferdam and the steel sheet pile double cofferdamthat had been constructed during the emergency restoration work, the embankment foundation was replaced,
impermeable steel sheet piles were installed to prevent water leakage thorough embankment, and the embankment andbank protection work was carried out and completed at the end of May.

Photo 2.1 Flooding situation in Joso City,
Ibaraki Prefecture (9/10)15) (Provided by
Kanto Regional Development Bureau,
Ministry of Land, Infrastructure, Transport
and Tourism)

Fig. 2.1 Rough cofferdam, steel sheet pile double
cofferdam/standard sectional view 16) (Provided by
Kanto Regional Development Bureau, Ministry of Land,
Infrastructure, Transport and Tourism)11Volume 7, Issue 4

December 2022

(2) Heavy rain in July 2018 (Western Japan Heavy Rain): The backwater phenomenon caused severe damage, the worst
flood in the Heisei period (1984-2019).
The seasonal rain front, which had been stationary in northern Japan since June 28, moved north toward Hokkaido on
July 4, then moved south to western Japan on July 5, and remained stationary near western Japan until July 8. Typhoon
No. 7, which had occurred in the south of Japan on June 29th, moved north over the East China Sea, passed out into the
Sea of Japan, and turned into an extratropical cyclone at 3:00 pm on July 4th. After that, the warm and extremely humid
air continued to be supplied to the vicinity of Japan, and the record heavy rain fell over a wide area from western Japanto the Tokai region.
In Ehime, Okayama, Hiroshima and other prefectures, river floods and geo-disasters occurred one after another, leaving
245 people dead or missing in 14 prefectures. The number of victims of floods and geo-disasters surpassed the cases ofheavy rain and typhoon No. 10 in July 1982, turning out to be the worst disaster in the Heisei period. 6,767 houses werecompletely destroyed and 7,173 houses were flooded above the floor level. There were breaches of the riverembankments at 2 spots of the nationally managed rivers and 25 spots of the municipally managed rivers, and 2,581 geodisasters occurred in 32 prefectures16).
In Mabi-cho, Kurashiki City, Okayama Prefecture, low-lying land spreads at the confluence of the Oda River and the
Takahashi River, and there often occurs flood damage due to the backwater phenomenon. Although it was an area withhigh flood risk, urbanization was progressing rapidly with the development of railways and roads. In the Oda River, which
was affected by the Takahashi River whose water level rose because of the heavy rain, the backwater phenomenon caused
the embankment to burst for about 100m at the confluence region with the Takama River. In addition, there occurred
embankment collapses at 8 spots, and the water overflowed at 4 spots, flooding an area of 1,200 ha and flooding 4,600
houses (Photo 2.2). The turbid current that flowed into the floodplain surrounded by the embankments of the Takahashi
River and the Oda River had no place to escape in the closed area, and the maximum inundation depth reached 5m.
Many residents were unable to escape, and 51 people died.
The Oda River's emergency countermeasure work consisted of rough coffering of the embankment where it had collapsed
using sandbags and sheets. After that, a steel sheet pile double cofferdam was constructed behind the rough cofferdam
in order to construct a temporary embankment for temporary use. The construction of the steel sheet piles was carriedout around the clock (Photo 2.3), and the emergency work was completed in a total of 14 days (Photo 2.4).

Photo 2.2 Collapsed Odagawa embankment18)

Photo 2.3 Double cofferdam of steel sheet
piles driven 24 hours a day18)

Photo 2.4 Completion status of steel sheet
pile double cofferdam18)

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December 2022

3. For future disaster prevention and mitigation (the roles required of steel pipe piles, tubular sheet piles, andsteel sheet piles)(1) Social contribution to the realization of national resilience
Based on the lessons learned from the Great East Japan Earthquake, as a basic law to promote nation-building that shallprotect the lives and properties of the people from large-scale disasters and accidents, the "Basic Law for National
Resilience (2013 Law No. 95)" was enacted and enforced by lawmakers in 2013, and based on it, the Cabinet approved
the Basic Plan for National Resilience in June 2014. In this plan, as a basic concept, we will go beyond the scope of “disasterprevention” in the conventional narrow sense, and no matter what kind of disaster occurs,
1, The protection of human life shall be maximized.
2, Important functions of the state and society shall be maintained without being fatally damaged.
3, Damage to public property and public facilities shall be minimized.
4, Rapid recovery and reconstruction
with the above four items as the basic goals, it is proclaimed to promote "national resilience" to build a safe and secure
national land, region, and economic society with "strength" and "resilience." In addition, it states that the public andprivate sectors will vigorously pursue initiatives and comprehensively promote them across ministries and agencies incooperation with local governments.
Steel pipe piles, tubular sheet piles, and steel sheet piles, which have contributed to the construction of various new
infrastructures, are expected to contribute greatly to the realization of national resilience, taking advantage of their
excellent properties (strength, deformation performance, quality, workability, workability, etc.) to protect the country
from natural disasters as a clue to reduce disaster.
(2) International contributions to the realization of a better and more sustainable world
As in Japan, natural disasters occur frequently in all regions of the world, such as sea level rise due to global warming,
torrential rains and storms caused by growing tropical cyclones, accompanying wind and flood damage and geo-disasters,
as well as earthquake damage, geo-disasters , tsunamis caused by earthquakes and volcanic eruptions, etc. In order torealize a "sustainable and better world" in the future, it is essential to develop and rebuild infrastructure in every country
in the world. Confronting many natural disasters, while being overwhelmed countless times, Japan has advanced anddeveloped its goods and technologies. Japan should make use of its strengths and keep striving to contribute to theresolution of international issues in cooperation with other countries and international organizations.
Fortunately, steel pipe piles, tubular sheet piles, and steel sheet piles are ready-made products, and in extreme terms,
they can be transported anywhere in the world. In particular, since the press-in method makes it possible to constructtubular sheet piles and steel sheet piles with relatively small construction machines, it is an ideal method for emergency
measures and restoration work in the event of a natural disaster. While combining the convenience and performance ofsteel materials with the excellent workability of the press-in method, we would be more than happy if we could make aninternational contribution by aiming to spread this method all over the world

4. Conclusion
In this article, due to space limitations, we selected and introduced domestic disasters that have become important
occasions which turned out to demonstrate the significance of steel pipe piles, tubular sheet piles, and steel sheet piles.
It was discussed how steel pipe piles, tubular sheet piles, and steel sheet piles have contributed to disaster prevention,
mitigation, and disaster recovery. In addition, in the cases where unfortunately damage occurred but they failed tocontribute to disaster prevention or mitigation, the causes were explained.
In Japan, where natural disasters occur frequently, steel pipe piles, tubular sheet piles, and steel sheet piles have beenplaying an important role for infrastructure development and urban formation. With the exception of some cases, nofatal damage has been confirmed even in the massive earthquakes and giant tsunamis rarely seen in human history, suchas the Hyogo-ken Nanbu Earthquake (Great Hanshin-Awaji Earthquake) and the Tohoku-Pacific Ocean Earthquake (Great
East Japan Earthquake). In addition, it has been recognized again that it is a useful material that can greatly contribute toearly recovery after a disaster. This is synonymous with the fact that the characteristics of the material were fully
demonstrated because the construction had been appropriately conducted, which means that the importance ofconstruction was reacknowledged at the same time.
In the future, whereas there is an urgent need to respond to new issues such as the promotion of aging and earthquake
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Volume 7, Issue 4

December 2022

resistance measures as well as the development of disaster prevention bases, we are determined to continue to workwith steel pipe piles, tubular sheet piles, and steel sheet piles that would contribute to society while coordinating withthe construction, aiming for a safe and secure society.

REFERENCES
1) Keiki Mase(1978): Restoration works of buildings in Niigata Earthquake, Kiso-ko (The Foundation Engineering &Equipment, Monthly), Vol.6 No.11, pp.94-103. (in Japanese)2) National Research Institute for Earth Science and Disaster Resilience(1969): 1968 Tokachi Oki Earthquake Disaster
Report, National Research Institute for Earth Science and Disaster Resilience Research Report, p.46.(in Japanese)
3) Google Maps，https://www.google.co.jp/maps/@38.2311839,140.865029,19.25z, (accessed on August 27, 2022)
4) Kozai Club and Japan Association for Steel Pipe Piles (1995): Great Hanshin Earthquake Disaster Report on Steel Pipe
Piles Foundation (primary) revised version, p.6. (in Japanese)5) Kozai Club and Japan Association for Steel Pipe Piles (1995): Great Hanshin Earthquake Disaster Report on Steel Pipe
Piles Foundation (primary) revised version, p.25. (in Japanese)
6) Kozai Club and Japan Association for Steel Pipe Piles (1995): Great Hanshin Earthquake Disaster Report on Steel Pipe
Piles Foundation (primary) revised version, p.13. (in Japanese)7) Shimizu Institute of Technology (1995): 1995 Great Hanshin Earthquake Disaster Report, p.117, (in Japanese).
8) Kobe Port Office, Kinki Regional Development Bureau, Ministry of Land, Infrastructure, Transport and Tourism:
Footprint of recovery from Hyogo-ken Nanbu Earthquake/ Disaster prevention of Port/ To know Port,
http://www.pa.kkr.mlit.go.jp/kobeport/pdf/know/shinsai_sokuseki.pdf, (accessed on September 16, 2022) (inJapanese)9) Ministry of Land, Infrastructure, Transport and Tourism Water Disaster Management Bureau (2005): Disaster
Archipelago 2005，p.39，https://www.mlit.go.jp/river/pamphlet_jirei/bousai/saigai/2005/, (accessed on September
16, 2022) (in Japanese)
10) Preservation Project of Photographs at 2011 Great East Japan Earthquake, Yahoo ！ JAPAN, https://archiveshinsai.yahoo.co.jp/, (accessed on September 7, 2022)
11) Japan Technical Association for Steel Pipe piles and Steel Sheet Piles (2011): Great East Japan Earthquake Primary
Disaster Report, p.6, (in Japanese)
12) Japan Technical Association for Steel Pipe piles and Steel Sheet Piles(2012): Great East Japan Earthquake Secondary
Disaster Report, p.16, (in Japanese)
13) Japan Technical Association for Steel Pipe piles and Steel Sheet Piles(2013): Constructing tomorrow, Vol. 81, p.5, (inJapanese)
14) Japan Technical Association for Steel Pipe piles and Steel Sheet Piles(2015): Constructing tomorrow, Vol.83, p.9, (inJapanese)15) Ministry of Land, Infrastructure, Transport and Tourism, Kanto Regional Development Bureau(2015): Information on
September 2015 Heavy Rain in Kanto/Tohoku Region, https://www.ktr.mlit.go.jp/bousai/bousai00000167.html，(accessed on September 16, 2022), https://www.ktr.mlit.go.jp/bousai/bousai00000171.html, (accessed on
September 16, 2022) (in Japanese)
16) Japan Technical Association for Steel Pipe piles and Steel Sheet Piles(2021): Looking backward to the past half century
and looking forward to the next half century, Commemorative Issue of 50th Anniversary of Japan Technical Associationfor Steel Pipe piles and Steel Sheet Piles, p.129. http://www.jaspp.com/topics/50th_anniversary_magazine.html,(accessed on September 16, 2022) (in Japanese)17) Cabinet Office (2018): Situation of July 2018 Heavy Rain Disaster, Disaster Prevention Information,
https://www.bousai.go.jp/kinkyu_index.html, (accessed on September 16, 2022) (in Japanese)18) Ministry of Land, Infrastructure, Transport and Tourism, Chugoku Regional Development Bureau (2019): Record of
July 2018 Heavy Rain~Disaster Response by Chugoku Regional Development Burea~, 385p.
http://www.cgr.mlit.go.jp/photo/h3007gouu_kiroku/index.htm, (accessed on September 16, 2022) (in Japanese)◆ A brief CV of Mr. Toshiharu Hirose

After graduating from Shibaura Institute of Technology in 1987, Hirose joined Kubota Corporation
where he was involved in developing demand for steel pipe piles in the construction market, technicalstudies on design and construction, and development of construction methods, etc. In June 1989, hejoined the activities of the JASPP. He has served as the chairman of the Technical Committee from2004 to 2021. Currently, He is involved in the management of the JASPP as the Technical Director of
the JASPP.

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Volume 7, Issue 4 December 2022

Interview Report
A novel pile extraction method: The best practical use of the
GEOTETS Method (Simultaneous backfilling during pile extraction)
Tsunenobu Nozaki
General Manager, GIKEN LTD.

Fig. 1 Overview of GEOTETS Method
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Volume 7, Issue 4 December 2022
Foreword
When temporary retaining walls are required, prefabricated piles such as steel sheet piles are often utilized since they
can be extracted and reused optimizing economy. However, the process of pile extraction may cause ground displacement
due to voids which occur during pile extraction. The extent of the problem of ground displacement is not normally easy
to predict, and robust solutions to this had not been in place until recently.
The GEOTETS Method (simultaneous backfilling during pile extraction), which can analyze and minimize the grounddisplacement risks, has been attracting attention in recent years. In this report, the IPA interviewed the GEOTETS Method
Research Society to get to the core of the method and its future potentiality.
Name of the method: GEOTETS Method (simultaneous backfilling during pile extraction)
Interviewee: Mr. Hiroaki WATANABE, chairman of GEOTETS Method Research Society (Hyogo, Japan)
URL: https://www.hikinuki.jp/

Mr. Yasuhiko NISHICEO of Civil Assist Co., Ltd., Kyoto, Kyoto, JapanMr. Hiroaki WATANABE
Chairman of the GEOTETS Method Research Society

Hiroshi YOKOTA, Professor Emeritus
at University of Miyazaki(Co-researcher)

Yoshinori FUKUBAYASHI, Associate Professor
at University of Miyazaki(Co-researcher)

Q1: What is the GEOTETS Method (simultaneous backfilling during pile extraction)
Steel sheet piles are currently the most popular retaining wall pile materials to be extracted and reused in theconstruction of temporary retaining walls. With the GEOTETS Method, injection pipes (small diameter steel pipes) used
for backfilling are installed adjacent to the sheet pile retaining walls before sheet pile extraction. Spacing between
adjacent injection pipes differs, depending on site conditions. The typical spacing is every 6 sheet piles. The dual
component reactive backfilling materials are mixed on-site and discharged from the tip of the injection pipe,
simultaneously with pile extraction. Generally, the backfilling material is around 4 times the volume of the sheet pile(minimum two times). However, this may need to be adjusted in accordance with the actual void volume and other site
conditions.
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Volume 7, Issue 4 December 2022

The backfilling material does not harden while fluid, but only when standing. Thus, voids can be fully backfilled with thematerials. Moreover, only absolute minimal alkali contents of the material seep into surrounding water, therefore, themethod is also environmentally friendly. The sequence of the GEOTETS Method is described in Fig. 2, Fig. 3 and Fig. 4
below.

Fig. 2. Sequence of GEOTETS Method

Fig. 3. Insertion of injection pipe

Fig. 4. Backfilling (above water)

View the webpage of GEOTETS Method Research Society for more details.
17Volume 7, Issue 4 December 2022

Q2: What inspired you to develop the method? Please tell us about the background of the development.
Removal of retaining walls may cause ground displacement due to voids which occur during pile extraction. However, therisk of ground displacement is sometimes disregarded or ignored despite its importance. Even if it had been considered,
there had not been a robust solution to ground displacement, and the problem has remained in the construction industry
for a long time.
In the past, cement & bentonite grout injection was generally utilized to fill voids caused by pile extraction. However, it
was not practical to carry out injection works concurrently with pile extraction. As a result, the surrounding ground wasleft unstable for a certain period of time after pile extraction, which sometimes caused ground displacement. This
fundamental problem has been known for more than 20 years in the industry and the GEOTETS Method inventor wasoften asked if this problem could be overcome. In order to meet industry expectations and satisfy his desire to develop
an original method, he decided to put his idea to practical use. He implemented his concept of “simultaneous backfilling”
to minimize risks of ground displacement. Furthermore, he deemed that his technology would be backed by academic
theories, therefore, he cooperated with the University of Miyazaki at the early stage of his development.

Q3: Currently, how is the risk of ground displacement assessed, in the case of pile extraction?
We still see projects in which ground displacement risk is disregarded or ignored. According to “Specification for
Temporary Structures of Road Earth Works (1999 Edition, Japan Road Association)”, the theoretical extent of grounddisplacement typically reaches 45°+φ/2 as shown in Fig. 5. Where the extent of ground displacement is concerned, themagnitude of the displacement is normally estimated taking the pile installation method, excavation sequence, lateral
deformation of retaining walls and pile extraction method into consideration. However, depending on ground conditions,
it is known that the actual extent of ground displacement sometimes reaches further than the formula (45°+φ/2) suggests.
It may be up to 2-3 times the pile length. Thus, we think that the risks of ground displacement are greater than thetheoretical formula stated in the specification.

Fig. 5. Theoretical extent of ground displacement due to pile extraction

Q4: Please tell us about process of bringing the method to the market?
We first brought the method to the market in 2007. After that, at the introduction stage of marketing, our brandrecognition was not widespread and the majority of inquiries we received were kind of SOS inquiries, which required
urgent remedial works after ground displacement had occurred. It took us quite a long time to disseminate information
to people about the risk of ground displacement. However, after the method gained recognition to a certain degree with
the increase in method usage, the majority of inquiries we receive nowadays are ground displacement prevention rather
than SOS inquiries. Regarding the GEOTETS project achievements, there were 130 project applications in 2021 and 530
in total as of June 2022.

Q5: How does the GEOTETS Method Research Society assess incoming inquiries?
It is not easy to measure the magnitude of the ground displacement in advance. However, the GEOTETS Method ResearchSociety is able to estimate both the extent of ground displacement and settlement to a certain degree by utilizing the
Peck’s formula, based on the given geotechnical investigation report and examining previous project data. We compile
an estimation and similar project data as a report and submit it to the project owner.
Nevertheless, how much risk they take is eventually up to the discretion of the project owner, taking into account thecost benefit performance on each project in determining the volume of the backfilling.
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Q6: It is sometimes the case that sheet piles are left in place even if they are for temporary use, due touncertainties of the potential risk of ground displacement. If this is excessive risk aversion, is it
avoidable by utilizing the GEOTETS Method?
Certainly, the GEOTETS Method enables project representatives to minimize the risk since that was the reason for its
development. In fact, project representatives who do not want to leave temporary sheet piles in place because they may
become obstacles in future development if they are left in place, often rely on the method. Specifically, it is against thelaw to leave temporary material in public land in Japan so the GEOTETS Method is quite often specified on projects.
“Extractability” and “Reusability” are the biggest advantages of steel sheet piles. These advantages are not a factor withregard to cast in-situ bored pile walls, or slurry walls. Therefore, we would appreciate it if people could maximize theeffectiveness of steel sheet pile solution by utilizing the GEOTETS Method.

Q7: What project information is required when inquiring about the GEOTETS Method for a particular
project?
The GEOTETS Method Research Society requires information about ground conditions, type of pile installation andextraction method, excavation sequence, type of temporary frameworks or anchors, lateral deflection of the retaining
wall related to excavation, allowable ground displacement (lateral movement and settlement) to assess actual extent andamount of ground displacement.

Q8: Does the GEOTETS Method have other advantages rather than minimizing ground displacement?
Although it is not the objective of the method, the backfill material lubricates sheet pile surfaces, which reduces pile
extraction resistance force, resulting in shorter construction time and a reduction in were and tear on the piling machine.
In general, sheet pile cut-off walls are left in place when being used in contaminated soil to prevent contamination
seepage. However, they can be extracted if the GEOTETS Method is utilized since the gelatinized backfill material isconsidered impermeable. Thus, the cost of sheet pile material can be minimized. The typical coefficient of permeability
k of the gelatinized backfill material is around 1.0x10-6cm/s.

Q9: What is the applicable depth for the GEOTETS Method?
Although the deepest application up to now is 40m, our goal is to reach 50m in the near future.

Q10: Can the GEOTETS Method be carried out in a cold weather environment?
As with cold weather concreting, it can be carried out if the backfilling material is cured for the cold weather environment.

Q11: Can the GEOTETS Method be carried out in restricted headroom, such as under overhead
obstructions?
Restricted headroom does not cause any concern, as injection pipes (minimum 1.5m) can be spliced and lowered to therequired depth.

Q12: Are there any unfavorable working conditions for the GEOTETS Method?
Attention must be paid if the groundwater flow velocity is 1.0x10-2cm/s or greater. If so, the solidification of the backfillingmaterial might be corrupted.

Q13: Up to now, all applications of the GEOTETS Method were carried out in Japan. Are there any plans
to implement the method outside of Japan?
We acquired a patent for the method at the initial stage of the development, eyeing the global market. As the first stepof expanding overseas, we have established an office in Vietnam and employed Vietnamese engineers there. We alsoplan to penetrate into Thai and Singapore markets sometime in the future. From these bases, we will expand our businessfurther into the South East Asian market.
In order to disseminate information about the GEOTETS Method to the global market, we also plan to establish an English
webpage describing the method.
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Volume 7, Issue 4 December 2022

Q14: We have heard that one of the issues with the GEOTETS Method is that it is not fully documented.
Do you have a plan to fully document the underground backfilling sequences of the method?
530 projects utilizing the GEOTETS Method have already been completed, and we can supply sample case histories toassess similar upcoming projects. Although we need to do this on a case-by-case basis at the moment, we could compile
the know-how into a technical document or specification and open it to the public.
Another challenge is to improve the accuracy of predicting the volume of the backfilling material, depending on working
conditions. As we accumulate case histories and analysis results of the method and put these into a database, we would
eventually be able to picture the situation below ground.

Q15: Please tell us about your predictions for the future. Do you have a target number of actual
applications and/or corporate members?
Basically, it is ideal if both pile extraction and backfilling are carried out in one operation, by the same company. Therefore,
we would like IPA corporate members to be members of the GEOTETS Method. As a short-term goal, we are targeting
200 applications in the year 2022.

Q16: Please proffer your message to people in the industry.
It will be more and more emphasized to reuse temporary retaining wall materials, in terms of reducing the risks of
obstacles in future developments, SDGs and decarbonization. However, currently in the construction industry thepotential risk of ground displacement due to the extraction of retaining walls, tends to be underestimated. Therefore, if
proper countermeasures are not in place during extraction works, it may result in undermining the advantages of reusing
temporary retaining wall materials. As we stated previously, we would dissuade people from relying completely on orunderestimating the risk with the theoretical formula of the extent of ground displacement (45°+φ/2). To reiterate, theactual extent of ground displacement sometimes reaches further than the formula (45°+φ/2) suggests.
In the future, with further dissemination of the GEOTETS Method, we want to develop a better formula than the current
one, which can be adopted in standard construction guidelines or specifications.

20Volume 7, Issue 4 December 2022

Report11th IPA Board Meeting in Singapore
IPA Secretary

The 11th Board of Directors Meeting was held on Thursday, 17 November 2022, in Singapore with an attendance of 17
directors onsite and 3 directors online. Due to the Covid-19 pandemic, it was the first time to hold a meeting physicallysince Prof. Leung was elected as IPA’s president.
Before the Board meeting, the meetings of the Standing Committee including the Administration Committee, ResearchCommittee, Development Committee, Publicity Committee, and Award Committee were held separately. Every
committee reported their activities of FY2022 and shared their opinions and advice.
The following agenda was discussed in the Board meeting.
・Activity report by President
・Progress reports of Standing Committees
・Establishment of Nomination Committee
・Progress reports of ICPE2024
・Next Board meeting in JapanThe Secretary General, Mr. Yaegashi, was retiring from IPA and Prof. Leung stated that he would let the Directors know byemail when he would appoint the new Secretary General according to the Constitution.
After the Board meeting, all directors were invited to visit the National Singapore University (NUS) which will be the venueof ICPE2024. The next Board meeting will be held on June 2023 in Kochi, Japan.

Photo 1 Board meeting in Singapore

21Volume 7, Issue 4 December 2022

ReportFrom Europe Regional Office (Netherlands)
Yuta Kitano
Technical Assistant Manager
Giken Europe B.V.

Introduction
The Europe IPA regional office is Giken Europe B.V. which is a subsidiary of GIKEN LTD. The office was moved from the UK
to the Netherlands in 2020. It mainly oversees the European market. Giken Europe is providing services consisting of
construction method proposal, rental/sales services of our machines, technical instruction for a piling operator and team,construction planning and design support, and machine maintenance.
The Press-in Method in Europe
We have received a lot of inquiries about our method or machines from a lot of countries. If I say something about theNetherlands where I am living, they are attempting to renovate the huge number of aging quay walls, including those inurban areas such as the city of Amsterdam, Den Haag, and the others located in very narrow spaces that are adjacent toa road, train rail, water traffic and so on. The quay wall itself is also a historical structure. Therefore, caring out renovation
within a compact space and minimum nuisance is required. Therefore, we can see the Press-in Method a lot in the urban
area. I feel that the Press-in Method with a sheet pile is getting normal here, while it is also getting to be interested in
Gyropress Method™, which is a method to install a steel tubular pile with rotation by utilizing the press-in principle. It isa more efficient way to the renovation of a quay wall because it does not require any temporary works, such as temporary
sheet pile, to remove existing quay wall. (More details are available on the website: https://www.giken.com/en/wpcontent/uploads/press-in_gyropress.pdf).
The first project using Gyropress Method was completed this summer with very good feedback from people involved inthis work. So, I believe that Gyropress Method is suitable for the Dutch and European markets. And next project using
Gyropress Method started this November. We are planning to show this incredible solution to the European market
through this project.
Recent Case Study in Den Haag, the Netherlands
You can see a video here https://www.youtube.com/watch?v=ZnVy9whGUGg
If you used a traditional way in is project, it would be necessary to install sheet piles in front of an existing quay wall as a
cut-off wall, pump-up water inside the wall, remove the existing quay wall then make a new concrete wall there. It needs
space for the works and needs to remove trees in the area, and stop all the traffic. While Gyropress Method can install atubular pile into an existing quay wall by using cutting teeth attached to a pile toe and rotation torque, which means it
does not need to secure a space, remove trees, and stop traffic. Also, less work is demanded, so it leads to a shorter
period of construction.
The project information is as below.
BackgroundThe city of Den Haag has jurisdiction over approx. 62 km of quay walls in total. Of these, approx. 23 km of wooden
foundations need to renovate for the following reasons.
 Most of the quay walls are 100 years old construction.
 Many of the wooden foundations have suffered from bacterial damage.
 Increased loads on the quay walls due to increased traffic such as cars and trams.
 Project Owner: Municipality of Den Haag Main contractor: collaboration (combination) of Van Gelder and Gebr. De Koning

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Volume 7, Issue 4 December 2022

Piling InformationConstruction length: approx. 44.0 m
Pile: steel pipe pile φ609.6
Pile length L=9.5 m

Fig.1 Under construction & Cross section
Recent Case Study in Berlin, Germany
Giken Europe has completed works using the Implant™ Method
and GRB™ System with the Press-In Piling technology reinforcing
a railway embankment in Berlin, the capital of Germany. The
project site was located in a confined space adjacent to aresidential district and live railway which was an excellent
opportunity to demonstrate the benefits of GRB System. GRB
System contains SILENT PILER™ F401-1400 (double-U), POWER
UNIT on UNIT RUNNER™ UR3, CLAMP CRANE™ CB3-6 and PILERUNNER™ TB18. All piling works were completed on top of theinstalled piles and eliminated the need for temporary platforms
and workspaces for cranes, materials and other construction
equipment. Construction works were completed without
affecting residents, existing infrastructure or train operations.
Giken Europe B.V. provided technical consulting and installation
work. The installation work utilizing GRB System attracted theattention of many construction parties who visited the site.
Project owners, consultants and contractors are seeking to adopt
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Fig.2 Cross section

Volume 7, Issue 4 December 2022
GRB System in other projects. They have begun considering other railway embankment reinforcement projects. The
GIKEN Group expects to expand the adoption of the Implant Method and GRB System across the German market.

Fig.3 Under construction
Information






Project Owner: Deutsche Bahn (DB) AG Netz
Main contractor: Company Echterhoff Bau GmbH, Berlin
Number of piles: 187 pairs (374 sheets)
Pile: U type sheet pile (GU27N)
Pile length L=7.25 to 10.25 m

Future Prospects for the Press-in Method in Europe
As mentioned above, some projects using the Press-in Method, Gyropress Method and GRB System were implemented
or will start. In the meantime, we are feeling that these methods are suitable for the European market. We are definitely
certain that our methods will be able to make their life and construction better.
Moreover, a structure built by piles is very efficient for future renovation because only removing piles and re-install new
piles are required.
Thus, we would like to show more and more advantages of our methods to the markets through the coming projects. If
you are interested in our activities and solutions, please contact me!
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Volume 7, Issue 4 December 2022

Event Report

Global Best Practices of Press-in Piling Method - IPA 15th
Anniversary Seminar in Singapore IPA Secretary
The Global Best Practices of Press-in Piling Method - IPA 15th Anniversary Seminar in Singapore - was held by International
Press-in Association (IPA) on 18 November 2022 in Singapore and it has been the first time to hold the event in physicallysince the Covid-19 pandemic started. IPA was founded in February 2007 and this seminar was held to commemorate the15th Anniversary of the Association. A total of 91 participants attended this seminar including IPA Directors from 11
countries, consultants, contractors, and geotechnical engineering practitioners.
To further commemorate this special occasion, the seminar commenced with experts presenting the most recent
advances in the applications of Press-in Piling in Asia, Europe, North America, South America, and Africa. Many of theseprojects such as coastal protection are highly relevant to Singapore and Southeast Asia. The past, present, and future of
IPA were also presented as follows:◆ Program:Presentation 1

Brief introduction of IPA and Press-in Technology
Mr. Hisanori Yaegashi (Japan)
Secretary General, IPA

Presentation 2

Remembering the early days of Press-in Piling research
Prof. David White (United Kingdom)
Professor, University of Southampton

Presentation 3

Recent applications to the Press-in Piling Method in Asia with emphasis on coastal protection
Mr. Hiroki Kitamura (Singapore)
Giken Seisakusho Asia Pte., Ltd.

Presentation 4

The application of Press-In Piling to increase the resilience of critical infrastructure in Europe
Prof. Kenneth Gavin (Netherland)
Professor, Delft University of Technology

Presentation 5

Recent Notable Press-in Piling Projects in North America
Mr. Takefumi Takuma (United States)
Giken America Corp.
Recent application of Press-in Piling Method in Brazil: Downstream retaining structures for
tailings dams
Associate Professor,
Dr. Marcos Massao Futai (Brazil)
Geoinfra University of Sao Paulo
Recent applications of the Press-in Piling Method in Africa: Senegal and Egypt case histories
Professor, University of Tunis El Manar - National
Prof. Mounir Bouassida (Tunisia)
Engineering of School of Tunis Recent research on the use of Press-in Piling data
Mr. Yukihiro Ishihara (Japan)
Manager, GIKEN LTD.

Presentation 6

Presentation 7

Presentation 8
Presentation 9

Future of IPA

President, IPA
Emeritus Professor, National University of Singapore

Prof. Chun Fai Leung (Singapore)Prof. Leung, the President of IPA remarked that the Press-in methods have new applications in his presentation. These
applications are multi-disciplinary in nature involving Civil engineers for construction, Mechanical engineers for machineand equipment innovation and development, Climate engineers for evaluation of water level rise, Coastal engineers forevaluation of impacts on seafront structures, Environmental engineers for evaluation of effects of new construction on
the environment and Others. He also announced that the ICPE 2024 will be held from 3 to 5 July 2024 in Singapore andexpressed his appreciation to all participants, and organizers at the final.

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Volume 7, Issue 4 December 2022

Photo 1 The venue of seminar

Photo 2 Prof. Leung is presenting

After the seminar, 46 people attended a live site press-in pilingdemonstration. The project is the construction of a private 2-storey
house. On the project, the press-in piling method is being utilized to
install Zero Sheet Piles (NS-SP-J Sheet Piles) which form anapproximately 12m x 27m rectangular shape retaining wall, for theconstruction of a single-level underground parking lot Right on theboundary lines to maximize land use, 9m long sheet piles were being
installed by the Zero Piler. Type of the Press-in Piling Method isknown as the “Zero Clearance Method”. The sheet piles are to be left
in place as permanent basement walls, in conjunction with cast insitu concrete walls. The ground condition is soft-medium stiff clay(old alluvium) with the maximum SPT N value of 14. The Standard
Press-in Mode (no driving assistance used) was utilized taking the
ground conditions into account.
According to the contract managing director, Mr. David Liaw Wie Seinof Guan Chuan Engineering Pte., Ltd., the Zero Clearance Method is
the most suitable for the construction of substructures in dense
residential areas where construction nuisances are unacceptable. In
addition to that, he stated “The method also enables project owners
to maximize the dimension of the substructure, by constructing itright next to the boundary lines.”
Since it is crucial to maximize land use in urban areas, the IPA
envisages that the Zero Clearance Method will also gain popularity inother countries.

Photo 4 Group photo

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Photo 3 Site Visit

Volume 7, Issue 4 December 2022

Event Report

Workshop: Earth-Fill Dam Anti-Seepage Solution by using Pressin Piling Method with Steel Sheet Pile applied to reservoirs
Vu Anh Tuan
Associate Professor, Le Quy Don Technical University, Vietnam
Director of IPA
On 14th October 2022, in Bac Kan province of Vietnam, Directorate of Water Resources (Ministry of Agriculture and Rural
Development) in collaboration with the Department of Agriculture and Rural Development of Bac Kan province and theJapan International Cooperation Agency (JICA) held a workshop "Earth-fill Dam Anti-seepage Solution by Using Press-in
Method with Steel Sheet Pile Applied to Reservoirs”. Co-chairs of the workshop included Mr. Dong Van Tu - Deputy
Director of Directorate of Water Resources, Mr. Ha Kim Oanh - Deputy Director of Department of Agriculture and Rural
Development of Bac Kan province and Mr. Tomohisa Ozawa - Representative of JICA. About 150 delegates from several
Directorates of the Ministry of Agriculture and Rural Development, some Research Institutes, Universities, Irrigation
Construction Investment Management Boards and representatives of Departments of Agriculture and Rural Developmentof 16 provinces attended the workshop. As for the International Press-in Association (IPA), Prof. Matumoto Tatsunori (VicePresident of IPA) and Assoc. Prof. Vu Anh Tuan (Director of IPA) attended the workshop.

Photo 1. Mr. Dong Van Tu - Deputy Director of Directorate of Water Resources presents the opening speech.
Press-in technology is a static pile pressing
technology which is capable of reducing noise andvibration during construction instead of the
traditional methods of pile construction by
driving or vibrating hammer methods. Press-in
technology can be used in places with extremely
limited conditions such as difficult terrain, limited
space, limited noise, on slopes, and on water...
Press–in with augering and Gyro Piler haveovercome the limitations of the traditional
method of static pile jack-in which is notapplicable where there is difficult geologicalground such as hard ground, rock and gravel
ground (Photo 2).

Photo 2. Press-in method to install sheet piles into hard ground27

Volume 7, Issue 4 December 2022
Five keynote lectures related to Press-in technology were presented at the workshop, as follows:
1. “Introduction on Press-in technology”, by Joint venture Ozawa Dobuku-Hashimotogumi;
2. “Introduction on Vietnamese standard for sheet pile, construction and supervision”, by Dr. Thai Quoc Hien (Institute ofHydraulics/Ministry of Agriculture and Rural Development of Vietnam);
3. “Survey report in Vietnam”, by Assoc.Prof. Le Thanh Hung (Thuy Loi University);
4. “Numerical analyses of an earth dam reinforced by steel sheet piles: Influence on water shielding and slope stability”,
by Prof. Matsumoto Tatsunori (Kanazawa University and Vice President of IPA);
5. “Handbook of Press-in retaining structures”, by Assoc.Prof. Vu Anh Tuan (Le Quy Don Technical University and Directorof IPA).
Apart from attending the workshop, the delegates and experts also conducted a site visit to the Keo Coi Irrigation
Reservoir in Na Ri district, Bac Kan province (Photo 3). This project is expected to apply Press-in Technology to handle
water leakage through the dam and increase the overall stability of the structure.
Press-in piling technology can bring optimum solutions in concern with engineering technique, economy, environmental
friendship, and aesthetics, which traditional construction methods are impossible.

Photo 3. Site visit to Keo Coi reservoir, Na Ri district, Bac Kan province, Vietnam.

Photo 4. Organizing committee and keynote speakers.

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Volume 7, Issue 4 December 2022

Young Members Column
Ke ChenPh.D. student, Tongji University
I received my master's degree in Civil Engineering from Hunan University. Currently, I am a thirdyear Ph.D. student at Tongji University, Department of Geotechnical Engineering. Our researchgroup is mainly oriented to solving problems encountered in civil engineering practice, such as themechanical behavior of pile foundations for offshore wind turbines, rainfall-induced slope instability,
and structure-interface stability under dry-wet cycles. I have gained much experience in the fieldover the past three years since I joined our group at Tongji University. I have also learned how to
critically analyze experimental data and convert it into abstract physical laws that can be applied inengineering practice. I joined the International Press-in Association (IPA) on June 7, 2022, as a
student member.
In the past two years, our research group studied theinfluence of adsorbed film on the hydraulicproperties of unsaturated soil. We established aunified hydraulic constitutive model based on fractal
theory for unsaturated porous media, and the titleof the research work is “A fractal hydraulic model forwater retention and hydraulic conductivity
considering adsorption and capillarity”. The model
can describe the water retention characteristics andrelative hydraulic conductivity of unsaturated soil inthe entire suction range, as shown in Fig. 1. It isfound that the pore size distribution of the soils
mainly controlled the transport characteristics of
capillary water, but had a slight influence on thehydraulic properties of adsorbed water, which was
dominated by the type and content of minerals andspecific surface area of the soil.

Fig.1 Measured and predicted hydraulic properties of clay loam:(a) calibrated SWRC; (b) predicted kr-h curve
From: https://doi.org/10.1016/j.jhydrol.2021.126763

The earth's surface soils are unsaturated, however, most of the research in the literature is based on saturated soils, andtheir effective stress equation cannot be used to estimate the stress state of unsaturated soils. Therefore, developing amore generalized mechanical framework for unsaturated soils is necessary. My research currently focuses on themechanical behavior of unsaturated soils, including the strength characteristics and stress-strain relationship. In addition,
I am also interested in the mechanical response of the unsaturated soil-structure Interface. These studies are critical forevaluating the bearing capacity of pile foundations, earth pressure development of retaining walls, and slope stability
issues under wet and dry cycles. I understand that the International Press-in Association provides a great platform forengineers and researchers from different organizations and institutions to share their experiences and findings, which
help to develop innovative technology for the betterment of society.

29Volume 7, Issue 4

December 2022

Date

Venue

Event Dairy
Title■ IPA Events
https://www.press-in.org/en/event

The Third International Conference on Press-in
Engineering (ICPE 2024)
13rd IPA Press-in Seminar 2022 in Chiba

3-5 July 2024

Singapore

13 February 2023

Chiba, Japan■ International Society for Soil Mechanics and Geotechnical Engineering
http://www.issmge.org/events

16th International Conference on GeotechnicalEngineering

7-8 December 2022

Lahore, Pakistan

GEOSYNTHETICS 2023

5-8 February 2023

Kansas City, United States

International Conference on Advances in Structuraland Geotechnical Engineering

6 March 2023

Hurghada, Egypt

8th International Conference on Unsaturated Soils

2 May 2023

Milos Island, Greece■ Deep Foundations Institutehttps://www.dfi.org/events/

New Orleans,

6th International Conference on Grouting & Deep
Mixing

15-18 January 2023

Conference on Foundation Decarbonization and Reuse

21-23 March 2023

Amsterdam, Netherlands

SuperPile 2023

7-9 June 2023

Atlanta, Georgia

7-9 February 2023

San Diego, United States

United States■ Others
24th Annual International Conference & Expo30

Volume 7, Issue 4 December 202231

Volume 7, Issue 4 December 2022

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Volume 7, Issue 4 December 2022

Editorial Remarks from persons in charge
Dr. Vu Anh Tuan
(Associate Professor, Le Quy Don Technical University, Vietnam)
Warmly welcome to the IPA Newsletter, Volume 7, issue 4. I strongly believe that you
will find interesting and valuable information from reading this newsletter. On behalfof the persons in charge, I highly appreciate the authors and the secretariat for theirgreat contributions to this issue. Last month, on the occasion of the IPA 15th
Anniversary Seminar in Singapore, the director board of IPA had a meeting in person
after a long time of meetings online only. Also, the publicity committee had discussions
on the plan for publishing the newsletters. This is a real optimistic signal for the IPA
movements after over two years of Covid 19 pandemic. I hope that you will receive
more helpful information from reading the IPA newsletter due to the strong
collaborations of members of the publicity committee and other IPA members

Dr. Chen Wang
(Assistant Professor, Tongji University, China)
We are so glad that this IPA Newsletter has been successfully issued. All the people
who have dedicated themselves to preparing this issue are appreciated. Due to theefforts made by all the members, including researchers and technicians, in theassociation, significant achievements in both academic and commercial aspects havebeen made in the past years. Meanwhile, with the constantly organized or coorganized seminar, workshops, webinars, and conferences, the academic impact of IPA
is continually increasing. We are also glad to see more and more talented young
members from all around the world involved and assembled here because they are thefuture of the big family. In the next stage, we will focus on more valuable research
topics during the design, construction, and maintenance of the press-in piling
methods. On behalf of the editorial board, we wish you all the best for the coming newyear!

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