December 2022 No.96
Japanese Infrastructure Newsletter

IDI
Infrastructure

Development Institute—JAPANThe comprehensive quality control method for impervious embankment
New quality control based on the collaboration of the latest soil compaction theory and ICT
Total amount control of compaction energy & impermeability

Real time monitoring system
Internet server

BIM/CIM

Number of rollingcompaction Map

Soil stiffness
index Map

GPS

Acceleration
sensorImprovement of compaction
control standard

Persons concerned

Dry density

Newly allow(ii): Proposed method

Near infrared radiation moisture meter(i): Conventional method

Contour oflower limit
value ofcoefficient ofwater
permeability

Grain size analysis
using digital image

1.5Ec
1Ec

Field supervisor

Newly exclude

Lower limit of saturation (Sr min )Water content, w

Total amount control of water content &grain size distribution

CONTENTS
24th Infrastructure Technology Development Award 2022

1

The comprehensive quality control method for impervious embankment

2

Precast PC floor slab using UFC as waterproof layer

5

Evaluation method of residual structural performance for piers using artificial
intelligence

8

Infrastructure Development Institute – Japan (IDI)
Plaza Edogawa-bashi 3F. 1-23-6, Sekiguchi, Bunkyo-ku, Tokyo, 112-0014, JAPANInfrastructure Development Institute - Japanth

24 Infrastructure Technology Development Award 2022
Japan Institute of Country-ology andAs a result of examination, institutes andEngineering (JICE) was established as a publicresearchers with the following technologies wereinterest corporation to promote construction

awarded the 24th prizes.

engineering in Japan by conducting cutting-edge
research and development activities.

The grand prize is “The comprehensive
quality

As more incentives should be provided forcontrolmethodforimpervious

embankment”.

construction technology researchers and research

And the two excellence prizes are

institutes to enhance the level of construction“Precast PC floor slab using UFC as waterproof

engineering more effectively, JICE commenced

layer”,

Infrastructure Technology Development Award

structural performance for piers using artificial

with Coastal Development Institute of Technology

intelligence”.

and“Evaluation

methodofresidual(CDIT) under the auspices of the Ministry of Land,
Infrastructure, Transport and Tourism (MLIT).

The grand prize and the two excellence
prizes are introduced below.

37 technologies competed for the 24th
Infrastructure Technology Development Award. In

Any inquiries/ comments please contact to JICE :principle, the applicants’ technologies should have

Homepage: http://www.jice.or.jp/

been developed within the past five years and(Japanese version only)

applied to the real sites already.

E-Mail: webmaster@jice.or.jp.

1

Infrastructure Development Institute - JapanThe comprehensive quality control method for impervious embankment
New quality control based on the collaboration of the latest soil compaction theory and ICT
2. Contents of the Technology
This technology controls the factors that
determine the quality of embankment by using
ICT: (1) the grain size of embankment material,(2) the water content ratio, and (3) thecompaction energy. In addition, this technology
manages all of these factors (1) ~ (3) and (4), soil
stiffness index (SSI), using ICT (Figure-1).
In the past, hydraulic conductivity has
been managed indirectly by "dry density" and"water content ratio”.This technology has
developed a new management method in which"density" and "water content ratio" are replacedby "in-situ compaction energy" and "groundstiffness,"
respectively,
enabling
areal
compaction
managementofimpervious
embankments using ICT (Figure-2).
In addition, the control values of (1)~(4)were set considering the on-site compactionenergy (1.5 Ec in this case) and the lower limitof the saturation degree (Figure-1(5)).
The ICT construction management
information from (1) to (4) is integrated in thecloud to enable real-time, remote control ofcompaction management (Figure-1(6)).

1. Background and Opportunities forTechnological Development
In recent years, i-Construction, whichis construction using ICT, has been promoted
in Japan. In general earthwork, productivity
has been improved in terms of quality control,with global navigation satellite system(GNSS)-based quality control, in which in-situ
density tests are replaced by GNSS recordings.
However, GNSS-based quality control
cannot directly measure quality control items
on embankment. For this reason, the quality
control of impervious embankments such as filldams has not yet broken away from the multipoint control type of quality control based on alarge number of in-situ tests. As a result, timeand labor-intensive in-situ tests cannot be
omitted, and productivity has not been
improved, in the construction of impervious
embankments.

Figure-1 Outline of the comprehensive quality control system for impervious embankment
2

Infrastructure Development Institute - Japan

Figure-2 Comparison of new management method and conventional management method

Figure-3 Reduction in field density test

Figure-4 Construction speed

Figure-5 Comparison of quality test resultswith past dams (degree of compaction &permeability coefficient)

Photo-1 Remote monitoring

4. Effects of the Technology
In the Koishiharagawa Dam construction
project, the time required for in-situ quality
control tests was reduced by more than 1,300
hours (Figure-3).
Real-time remote confirmation of quality
control records became possible (Photo-1), andthe number of personnel required by theoperator was reduced to about half of thoserequired for dams of the same size in the past.

3. Scope of Application of the Technology
In order to apply this technology, it isnecessary to control the particle size
distribution of fill materials and the in-situ
compaction energy within a range that can be
regarded as constant.
Therefore, this technology is highly
compatible with large-scale impervious
embankment projects such as fill dam
construction, where compaction and material
management are carefully controlled.
3

Infrastructure Development Institute - Japan
6. Track Record of Application of theTechnology
Koishiharagawa Dam construction
project, impervious zone construciton, Oct
2017- jul 2019.

The construction speed of the core zone of
the fill dam (monthly fill height (m/month)) was
the fastest among fill dams over 100 m in Japan.
The average compaction degree washigher than that of dams constructed using theconventional management method (Figure-5).
All measured hydraulic conductivity values
satisfied the control values.

7. Contact Information
5. Social Significance and Development

Technology Developer:
Japan Water Agency ／ Kajima Corporation
Construction
Technology
Dept.
Civil
Engineering Management Division

Potential of the Technology
This technology has realized for the firsttime areal compaction control in impervious
embankment construction, which had been
considered difficult in the past. As a result, it
contributed to the promotion of i-Construction.
This technology is expected to be applied
to construction projects for impervious
embankments such as fill dams, riverembankments, and final waste disposal sites,
both in Japan and overseas.

https://www.water.go.jp
TEL:+81-48-600-6553
E-mail:webmaster@water.go.jp
http://www.kajima.co.jp
TEL:+81-3-5544-1111

4

Infrastructure Development Institute - Japan

Precast PC floor slab using UFC as waterproof layer
Floor slab of composite structure with UFC layer
the joints of precast floor slabs, thereby
waterproofing the entire bridge surface by UFC.
The joints between precast floor slabs and insitu UFC have a serrated shape (Figure-2,
Photo-2) to ensure waterproof performance andtransmit the tensile stress of the UFC.

1. Background and Opportunities forTechnological Development
Currently, expressway companies arestrongly promoting the replacement of steel
bridge floor slabs as a representative work of
expressway renewal projects. In these projects,
precast concrete floor slabs are used as thestandard for newly installed floor slabs in orderto improve the durability of the floor slabs andreduce the impact of long-term traffic
restrictions. Considering that it is important todevelop even more durable floor slabs to preventthe effects of long-term traffic restrictions, we
focused on the application of Ultra-highstrength Fiber reinforced Concrete (UFC),
which has high strength and excellent waterand salt barrier properties.
In addition, it has been difficult to shorten
the work schedule for on-site waterproofing
work for the floor slab, which is the last step of
highway construction work. Therefore, we havebeen hoping for a waterproofing system thatenables us to shorten the traffic regulation
period and be unaffected by the weather.

3. Scope of Application of the Technology
・Concrete floor slabs of steel road bridges

Asphalt Pavement

UFC
Figure-2

Field-Cast UFC
Floor SlabConnection

Figure-1 Outline of Precast PC floor slab with
UFC layer

UFC
layer
Connection

2. Contents of the Technology
This technology is a precast PC floor slab
with a composite structure in which dense,
high-strength, and durable UFC is layered andintegrated on the upper covering of the floorslab (Figure-1, Photo-1). The newly developed
composite PC slab provides a waterproof
function by replacing the upper concrete of the
precast PC floor slab with a UFC layer that is
20 to 40 mm thick, and also uses in-situ UFC at

Photo-1

Concrete

220mm

Concretelayer
Connection

Figure-2 Edge of Precast PC floor slab with
UFC layer

Precast PC floor slab with UFC layer
5Infrastructure Development Institute - Japan
4. Effects of the Technology(1) Shortening of the traffic restriction period for floorslab replacement work: Since floor slab
waterproofing work is not required on site, it ispossible to shorten the traffic restriction time
(Table-2).
(2) Avoiding the risk of delays in floor slab
replacement work: Since floor slab waterproofing
work cannot be carried out during rainfall, there isa risk that unseasonable weather will delay thework schedule and affect the traffic restriction
period. By applying the floor slabs of composite
structure, this situation can be avoided (Table-1,
2).
(3) Reduction of life cycle costs (LCC): Due to thehigh strength of UFC, the waterproofing functionof the floor slabs with UFC layers will not be
impaired even when the pavement is renewed
once every 30 years. In addition, labor savingsand LCC reduction can be achieved.
(4) Improved floor slab durability: By laying UFC
on top of a precast PC floor slab, the fatigue
durability of the floor slab can also be improved.

Photo-2
Precast PC floor slab connection
before filling UFC

Photo-3 Completed construction of Precast
PC floor slab with UFC layer

Table-1

Direct effects of Precast PC floor slabs with UFC layer (life cycle costs)(Unit: million yen)with UFC layer
Conventional
Increase/Decrease(A)technology (B)(A-B)
100 years LCC (a+b)
154
169
- 15
(a) Construction cost
154
26
+128
(incremental)(b) Maintenance cost
0
143
-143
Delay cost due to bad
0
17
- 17
weatherTable-2 Indirect effects of Precast PC floor slabs with UFC layer (traffic restriction period)(Unit: days)
with UFC layer
Conventional
Increase/Decrease(A)technology (B)(A-B)
Traffic regulation period
51
121
-70
through 100 years (a+b)(a) Regulation period for
34
37-3
floor slabs renewal(b) Regulation period for
17
84
-67
pavement renewal
Additional period due to
0
25-25
bad weather
6Infrastructure Development Institute - Japan
7. Contact Information

5.

Social Significance and Development
Potential of the Technology
By applying this technology, it is possible
to shorten the period of traffic restrictions
during floor slab replacement work, thereby
reducing the occurrence of traffic congestion
due to traffic restrictions, thus contributing to
the reduction of the impact on public life andsocial loss. In addition, since the conventional
floor slab waterproofing work, which had to be
renewed every 30 years, is no longer required,it contributes to labor saving and productivity
improvement in construction. It also
contributes to improving the durability of floorslabs.
The deterioration of road bridge floorslabs is progressing around the world, and webelieve that we can contribute to this problem
through the international deployment of thistechnology.

East Nippon Expressway Company Limited
Hidekazu Hayashi
Structural Engineering Section
Technology & Environment Departmenth.hayashi.ac@e-nexco.co.jp
Obayashi Corporation
Masumi Muto
Research&
Development
Management
Department
Technology Strategy Planning Office
Technology Divisionmuto.masumi@obayashi.co.jp

6. Track Record of Application of theTechnology
The floor slab replacement work on
Tohoku Expressway Miyagi Shiroishigawa
bridge from October 2020 to November 2020,
and 4 other projects.

7Infrastructure Development Institute - Japan

Evaluation method of residual structural performance for piers using artificial
intelligenceContribution to rational and planned maintenance by predicting the durable period of piers
2. Contents of the Technology
Our proposed technology makes it possible
to estimate the durability period of port
structures based on their residual performancethat indicates how deteriorated piers will bedamaged during an earthquake. The residual
performance of a pier depends on the degree ofcorrosion of the reinforcing steel bars in the
beams; however, chipping concrete each time
to measure the residual performance is notrealistic.
Therefore, we first fabricated beamspecimens corresponding to deterioration
degrees “a” to “d” by forcibly corroding thereinforcing steel bars. Next, we determined theflexural capacity of beam members throughstructural testing and reproduction analysis via
the Finite Element Method. Then, we createdskeleton models corresponding to eachdeterioration degree, and evaluated theresidual flexural capacity of the beam members
through structural analysis based on eachdeterioration degree.
In addition, by removing a portion of theaged pier beams for pier renewal work andconducting loading tests, issues with regard to
the effects of different corrosion methods ofreinforcing steel bars and scale effects wereresolved. Furthermore, by having the AI learn
the combination of structural analysis
conditions
andanalysis
resultsforapproximately 2,000 cases, we constructed an
AI model that outputs the degree of damage
from the degree of deterioration, and confirmedthat it can predict the degree of damage withhigh accuracy (Figure-3).

1. Background and Opportunities forTechnological Development
Of 58,839 public port facilities, 10,178
facilities were identified that require emergency
measures (as of March 31, 2019). In addition,
approximately 30,000 other port facilities are
owned by the private sector, which includes
steel, cement, and nonferrous metal companies.
Although inspections of port facilities havebecome mandatory with the revision of thePorts and Harbors Act, in many cases,
especially in the private sector, “breakdown
maintenance” is performed, wherein measures
are taken after a failure of a facility occurs(Figure-1). The degrees of deterioration andperformance degradation obtained frommaintenance surveys represent the condition of
the facility at the time of conducting the surveys.
Till date, there have been no rational
indicators to determine whether the facilities
can continue to be used or when repairs andreinforcements should be carried out (Figure-2).
Therefore, in this technological development,
we devised a tool for port piers to estimate thedurable period of port structures based on theirresidual performance and provide informationthat facilitates decision-making by facility
managers.

Figure-1 Port pier deteriorated due toreinforcing steel bar corrosion
8

Infrastructure Development Institute - Japan
Facility inspection

Degrees of deterioration and performance degradation
凡例■a ■b ■c ■d
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diagnostic parts

performancedegradation

beam

A

RepairandReinforcement

Figure-2 Flow of survey and diagnosis on current maintenance and management(a) 曲げひび割れ発生時
図-6時局終 )c((b) せん断ひび割れ発生時

時生発れ割びひ断んせ )b((c) 終局時

時生発れ割びひげ曲 )a(

図布分みずひと図布分れ割びひのルデモ析解と体験試な全健
健全な試験体と解析モデルのひび割れ分布図とひずみ分布図

Corrosion investigationof reinforcing steel bar

Evaluation ofresidual structural
performance

6-図Full model analysisof port pierFE analysis of beam

M

終局損傷
ultimate
降伏損傷
yield
ひび割れ損傷
crack
損傷なし
no
damageφ(a) 載荷前(b) 曲げひび割れ発生時
図-7(c) 終局時

時局終 )c(

時生発れ割びひげ曲 )b(

前荷載 )a(skeleton model
7-図梁のFEM解析

腐食した試験体と解析モデルのひび割れ分布図とひずみ分布図
図布分みずひと図布分れ割びひのルデモ析解と体験試たし食腐

Relationship between degree of deteriorationand flexural capacity of beams

Developmental technique 1
Creating skeleton model from degree of deterioration
凡例■a ■b ■c ■d

No corrosion

M

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degree “a”

φmoment M

Developmental technique 2
AI enables evaluation of residual structural performance
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弾性剛性を6割減
完全弾塑性

降伏損傷
損傷なし
損傷なし
yield
ひび割れ損傷
ひび割れ損傷nodamagecrack

Skeletonaa modelMof degree “a”
降伏

Figure-3 Flow of technological development

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健全モデル

Evaluation of residual

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凡例

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健全モデル
Deterioration
劣化度ａモデルdegree “a”

Evaluation of residual
structural performance

AI analysis■a ■b ■c ■d〇

FE analysis

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ultimateyield
structural performanceφ
損傷なし
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Figure-4 Example of residual structural performance using AI
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Infrastructure Development Institute - Japan
5. Social Significance and Development
Potential of the Technology
Our proposed technology makes it easy forfacility managers to obtain damage prediction
information and make decisions on whether tocontinue using the facility or to repair orreinforce it, thereby enabling a shift to rational
and planned “preventive maintenance”. This isof great social significance as it contributes tonational land resilience and economic
development. As we can construct AI models forstructures other than port piers, this system
can be used as a maintenance management
technology for various structures in the future.

3. Scope of Application of the Technology
Generally, the piers for which the residual
performance can be evaluated are vertical pile
structures. In many cases, piles are fabricatedusing anti-corrosion technology, and they are
meticulously maintained; therefore, the AI
model was trained on the assumption that piles
would not deteriorate.
In designing a pier structure, only theinertial force as the weight of its slab isconsidered against external forces such as
seismic forces, and the slab is generally notregarded as a structural member that resists
such external forces.

4. Effects of the Technology
Our AI-based evaluation technique makes
it possible for us to immediately identify the
specific beam members that will be damaged byseismic forces and their degree of damage.
In addition, by using a probability modelof deterioration progression, such as a Markov
chain model, together with this technology,
determining
thechangeinresidual
performance over time is possible, thus we canset a specific period during which piers canremain in service (Figure-4).
Furthermore, as predicting recovery
depending on various repair and reinforcement
patterns (the quantitative effects of repair andreinforcement) is possible, we can formulate arational maintenance and management plan.

6. Track Record of Application of theTechnology
Annual inspection of quays and port piers
owned by Nippon Steel Kobelco Shearing
Corporation, September 2021 to November
2021., and 1 other.

7. Contact Information
Technology Developer:
Kunihiko Uno , Dr.Eng. , Manager
Civil Engineering R & D Division,
Institute of Technology,
Penta-Ocean Construction Co., Ltd.
E-mail: kunihiko.uno@mail.penta-ocean.co.jp
TEL: +81-287-39-2109
FAX: +81-287-39-2131
HP: http://www.penta-ocean.co.jp/

10About IDI and IDI-quarterly
Infrastructure Development Institute-Japan (IDI) is a general incorporated
association operating under the guidance of Ministry of Land, Infrastructure,
Transport and Tourism of Japanese Government.
IDI provides consulting services to facilitate international assistance todeveloping countries, to promote international exchange of information and humanresources, and to support globalization of project implementation systems targeting
both developed and developing countries in the field of infrastructure.
IDI has been publishing a free quarterly journal called “IDI Quarterly”
since1996 to introduce information related to public works and construction
technologies developed in Japan, to foreign countries. We have distributed thejournal to administration officials in more than 90 countries around the world via email.
It will be highly appreciated if you could send us your opinions,impressions, etc. regarding the articles. We also welcome your specific requests
regrading technologies you would like to see on following Quarterly issues.

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