CAESAR
Center for Advanced Engineering
Structural Assessment
and Research,
Public Works Research InstituteCore research function in the Safety Managementof Road Bridges
The Center for Advanced Engineering Structural Assessment andResearch (CAESAR) is one of the five research units of Japan’s
Public Works Research Institute (PWRI). The PWRI, which was
founded with the inauguration of a road-material test center in the
Civil Engineering Bureau of the Ministry of the Interior in 1921,
has now a history of 90 years as a national research institution, an
independent administrative corporation, and a National Researchand Development Agency. Throughout its history, CAESAR has
established itself as the core research function in the formulationof technological standards for the construction of structures,
technology development, and disaster prevention measures.

Fracture of the truss member of
Kisogawa-ohashi Bridge

Besides exposure to heavy traffic demand and severe
natural environment, Japan’s infrastructures are startingto age, urging the development of technologies toevaluate the performance of structures to maintain andrenew them accordingly.

Collapse of a highway viaduct of Route 3, Koberoute, of the Hanshin Expressway during the 1995
Hyogo-ken Nanbu Earthquake

Therefore, the PWRI reorganized and developed theresearch units and founded CAESAR on April 1, 2008,
as an integrated research institution concerned withconstruction technologies dedicated to the safety
management of road bridges.

＜CAESAR’s Role＞
1. Technical support for Administrators
Technical support for Administrators can be described as providing diagnosis and prescription for the
structures having several technical issues, in response to the requests from road administrators. Thesedifficult issues may include damages or deformations caused by aging, earthquakes, and other natural
disasters, as well as design and construction problems. In addition, the data of each case are compiled as aknowledge base and offered to the site in the form of electronic information or a manual.

2. Research and Development
The researcher themes include improvement in the efficiency and reliability of maintenance cycles, as wellas technologies aimed at renewing or building new social infrastructures to prolong their useful life andmaintain them more efficiently. We also develop earthquake-resistant technologies to enhance the resilienceof infrastructure facilities. The results obtained are reflected in the formulation of guidelines of periodic
inspection and specifications of road bridges.

3. Dissemination and exchange of information
As an example of a “Dissemination and exchange of information,” we hold free events such as lectures andmeetings where the participants can gather and exchange the most recent technology-related information.
Acronym in English – The acronym CAESAR was inspired by Gaius Julius Caesar,
the hero who built the cornerstone of the Great Roman Empire, which spanned over a thousand years
with a solid grand design based on constantly innovative policies.
Cover Photos – Upper left: Field examination of a bridge that suffers salt damage; Upper right: Direct diagnosis of an aging
bridge; Lower left: disaster examination - The 2011 earthquake off the Pacific coast of Tohoku; Lower right: fluidization
countermeasure open experiment１

Technical Support for Administrators– Technical consultation –CAESAR collaborates with the National Institute forLand and Infrastructure Management (NILIM) to
provide technical consultations to road administrators
facing issues related to bridges and other structures.
We provide various forms of technical support toissues being faced by the road administrator of eachbridge, such as damages or deformations caused byaging, earthquakes, and other disasters, as well as
design and execution-related problems. Through close
cooperation with the administrators, we propose
methods to examine and evaluate the bridge,
diagnose the cause of the damages and suggest
reinforcement methods, dispatch technicians to thesite according to its request, etc.

Record of Technical Support for Administrative Bodies- Consultations about the safety of bridges under service account for the majority
Consultation regions
FY2006 and FY2007(before CAESAR)

Designphase

Execution

Under
service40%

80%(only bridges under service)※As of 08/01/2018

FY2016 and FY2017(after CAESAR)

0%

20%

60%

100%

Ratio of technical consultation

Rupture of PC wire of aconcrete bridge

Collapsed bridge after
an earthquake
Corrosion/Cross-sectional
defect in a pile ventNational expressways
Around 12,700
bridges 2%

National roads
Around 24,800
bridges 4%
Auxiliary roads
Around 30,600
Bridges 4%

亀裂
亀裂
Total
numberof bridges
Around690,700

Prefectural roads
Around 101,000
bridges 15%

Municipal roads
Around 521,600
bridges 76%

Crack detected at steel
floor slab
Damage by ASR

Number of bridges in Japanby road type 2 m or more
From the road statistics annual report 2017２

Technical Support for Administrators - Bridge Diagnosis The local governments that manage large numbers of facilities require increasingly more financial andtechnical support to counter the issue of aging roads. Since FY2014, the Ministry of Land, Infrastructure,
Transport and Tourism (MLIT) has conducted direct diagnosis on bridges that are more likely to require
urgent and high-level technical power, as a form of support measure to local governments. A direct
diagnosis by the head equator occurs when further assistance is required in consideration of the technicalcapacity of the local governments (e.g., cases with a complex structure, with severe damages, and highsocial importance) despite a rule that determines “road facilities such as bridges and tunnels must be
managed responsibly by each road administrator.” In such cases, the state dispatches a “road maintenancetechnical group” composed of personnel of NILIM and Regional Development Bureaus to provide technicaladvice. CAESAR then joints the technical group along with NILIM and gives technical support.

Scene of a direct diagnosis

Report from the road maintenance technical group to
the road administrators

Technical Support for Administrators– Technology Transfer to Local Engineers –In the management of structures, it is essential to continuously engage in the development of humanresources to maintain and improve the technical capacity of the local administrators that supports it. To thisend, we designate some of our personnel to give lectures on the design, construction, and maintenance ofroad bridges in technical training for in-house engineers of road administrators and public training institutionsof the state and local governments, as well as a wide range of technical courses dedicated to generaltechnicians.
In addition, by receiving technicians and researchers from road administrators (including local governments),
universities, and private companies to solve a problem together, we are constantly engaged in thedevelopment of human resources that support the management of structures. We believe that this initiative
can not only improve the individual technical capacity but also promote an internal technology transfer in theirorganization of origin.

３

Practical exercise of nondestructive
inspection to road administrators (carried out
as part of the training of the College of Land,
Infrastructure, Transport and Tourism)

Examination practice at an exhibition facility of removed
members (Carried out as part of the training of the College ofLand, Infrastructure, Transport and Tourism. The case isstudied with a deteriorated member who has been removed)

Technical Support for Administrators - Disaster relief Providing support to investigate and restore bridges afflicted by an earthquake is one of the most importantroles of CAESAR. In cooperation with NILIM, we receive the request from the road administrators,
investigate the damage, give advice on traffic regulation, provide support for urgent technical measures, andassist with emergency restoration and full-scale recovery plans. We also analyze the cause of the damages,
based on the examination results, and conduct research and development on countermeasure technologies.
When the earthquake struck the Pacific coast of Tohoku in March 2011, we immediately sent a group oftechnicians to the area and examined approximately 200 bridges. The investigation body during that period,
consisting of as many as 240 man-days with CAESAR technicians alone, conducted examination activities toprovide the bridge administrators with continuous technical support for emergency restoration and full-scale
recovery of the afflicted bridges.
After the Kumamoto earthquake of April 2016, a group of specialists from the PWRI team corresponding tonearly 200 man-days was dispatched to the area to verify the damages. In the case of areas that wereseverely affected, a group representing the state was responsible for disaster restoration. A restoration
analysis project team (PT) was formed for each road structure to conduct detailed analyses and study
restoration methods.

Technical support at the area affected by theearthquake off the Pacific coast of Tohoku in 2011

Damage examination of road bridges
following the Kumamoto earthquake

Contribution to the Restoration of Roads in Kumamoto Reconstruction ProjectIn the Kumamoto Reconstruction Project, we provided technical support concerning repair/reinforcement
methods and monitoring* through the Kumamoto Restoration PT. Alongside NILIM, the PWRI played aleading role in the project, contributing, for example, with an early resumption of the main route thatconnects the city of Kumamoto and the village of Minamiaso (including Aso-Choyo-ohashi Bridge).
* To verify the effects of the repairs during the execution

Restoration of Aso-Choyo-ohashi Bridge: In order to make it less susceptible to the influence of slope
failure because of weathering or earthquake in the future, and not to be fatal damaged, we advised theroad administrator on bridge structures, its alignment, and elimination of the unstable ground4

Research and Development – Improvement in Efficiency
and Reliability of Maintenance Cycles –The rapidly aging social capital of Japan is becoming a serious problem, causing deterioration-related
damages that result in fatalities, such as the accident in the Sasago Tunnel in 2012. To respond to such
issue, it is necessary to execute the maintenance cycles consistently and guarantee proper performance ofthe social capital. This study aims to provide solutions to the technical issues faced in each phase of themaintenance cycle (inspection/examination, diagnosis, execution (repair and reinforcement), documenting),
create a virtuous circle on the technical aspect of the maintenance cycle, and thereby contribute to ensuring
the soundness of the social capital.
①Inspection/Examination: technologies that improve the efficiency andreliability of examination and monitoring to generate a more reliablediagnosis②Diagnosis: Method of sorting out the parts that require action anddefining urgency (priority)

Inspection

Documenting③Execution: The best-suited maintenance and repair methods for the
existing phenomena and local conditions (evaluation of new technologies)

Diagnosis

Execution

Promotion of Clinical Research
There are many causes of deterioration damage or deformation of existing bridges, and not all of them can be
simulated in a laboratory. Therefore, it is necessary to adopt approaches such as medical science andcompile the cases, the examples of the dismantling of removed bridges, the experiments of residual strengthand repair and reinforcement effect using samples, followed by an epidemiological analysis to examine thedamage form by age. We call this series of studies using actual bridges “clinical research.” CAESAR, throughcollaboration with NILIM and in cooperation with MLIT Regional Development Bureau and local governments– the road administrators, is installing sensors in the bridges to observe the progress of deterioration anddamage and collecting members of bridges removed due to deterioration and damage.
Removedbridges

Loading test of removed bridges
Overall behavior measurement byloading test before removal(comparison with structural analysis;e.g., the combined effect of beams andfloor slabs and load distribution)
Test with loaded vehicle

・Damage state examination
・Visual inspection

Loading test using a part ofa removed bridge

Development of bearing capacity evaluation
technology according to damage state

Nondestructive examination
with removed beams
Development of
nondestructive inspection
technologies applicable toactual bridges and methods
to evaluate the performanceof these technologies
・Examination with various nondestructive
inspection technologies
・Examination opportunity offered to the privatewith actual bridges
Verifying the applicability of maintenancetechnology of the private promotes a practicaltechnology development.

5

Dissection of removed beams
Corrosion state of steel material(E.g., external damage state and residual steel)

Conditions of concrete(Amount of salt and crack progress status)

Arrangement of steel material(Old bar arrangement method)

Tensile test of extracted rebar(Strength test of old material)

After the on-site dismantling, pieces of the removed beam and member
are thoroughly dismembered at the lab to determine the damage state.

Performance Evaluation for Existing Bridges and its Repair/Strengthening Methods
As the periodic inspection progresses, the number of bridges requiring repair or strengthening is expected toincrease rapidly, but a method to select the most appropriate countermeasure according to each situation is
yet to be established. For this reason, we are engaged in the research and development of reliable repair andstrengthening technologies that do not end up in increasing the maintenance workload due to re-deteriorationor maintainability decrease.
Our goal is to establish the proper method to evaluate bridge performance including the load-bearing
capacity and thereby contribute to improving the diagnostic technique of road administrators of the entire
country. To verify the residual bearing capacity of an existing PC bridge that suffered salt damage, we
performed the first destructive test with the main beam of an actual bridge in Japan.

On-site loading test on a bridge to be removed, until it collapses

We are working to clarify the fatigue damage mechanism of concrete bridge decks strengthened with fiber
sheets and the required performance of strengthening materials. We are also proposing a design method forstrengthening the decks with the fiber sheets, which is compatible with various materials, and contributing to
the development of the most suitable method for maintaining and repairing the decks.
Peelingsurface
Loading
direction
Sheet after
peeling
Peeling

Sheet peeling in a flexural test

Sheet adhesion test

Development of Nondestructive Test and Monitoring Technology
CAESAR is engaged in the research of inspection technologies to determine the status of a bridge both
efficiently and logically, which includes a nondestructive inspection technology that reveals the internal
conditions of a structure and a measurement and monitoring technology that detects the occurrence andprogress of damages in a timely and efficient manner. We are also working to develop a maintenancemanagement system that includes a technology for storage and application of information.
Knowing that the steel inside the concrete members suffers
corrosion by salt damage, we developed, in collaboration with
The university of Tokyo and Riken, a technology that uses ahigh-power X-ray and neutron beam to visualize the problems
that are difficult to be detected in a regular inspection. This
enables to detect insufficient filling of grout and rupture ofsteel bars at deeper parts of the members, as well as theamount of salt in the concrete.

Rupture of a steel bar

Examination of concrete interior with X-rays

6

Research and Development – Research on Renewal and newly
construction of Infrastructure for Lifetime extension and Efficient Maintenance –Japan’s social capital stock was mainly built in the period of high economic growth, which raises the concern
about a rapid increase in the number of aged stocks. It is essential that these cases be renewed without
interrupting the related services. In order to steadily renew and build a new social infrastructure under harshfinancial conditions, it is indispensable to have a system that is precisely aligned with the level of importanceof each structure.
The road structures that compose the most vital routes of the country, for example, need to have highdurability and a low life-cycle cost and maintenance workload. On the other hand, there are smaller structures
that, despite not being demanding in terms of management, exist in vast numbers. For these cases, it isadvantageous to build a structure that allows to identify which parts require renewal, as well as when theyrequire it, with a simple inspection.
Therefore, this research aims to develop the material and evaluation method required to implement newtechnologies that suit the social needs as in the case above.

Methods to Improve the Quality and Reliability of New Bridges■Verification of applicability of dynamic loading test of single pile
We compared the results of ultimate bearing capacity measured by rapid loading test, one of the dynamic
loading tests, with the one measured by static loading test currently set as the standard.
The result of comparison shows the one measured by rapid
loading test is on the same level with the one measured bystatic loading test, and revealed that the rapid loading test
is applicable to the bearing capacity evaluation at the pilehead. Thus, we contributed to the rationalization andimprovement of the reliability which bearing capacity ofpiles is evaluated under complex soil conditions or when
applying a new construction method.
Rapid loading test (with an actual pile) being conducted■Analysis of Reliability Improvement in the detail category for expressing Fatigue Strength
To improve the reliability of the design andevaluation method of fatigue durability of steel
bridges, we analyzed the factors that influence thefatigue strength of welded joints using themultivariate analysis method and suggested whichtest conditions should be recorded as the fatigue
test data to be used as the basis of fatigue strength
setting.
Calculated with the conditions of “Current of 260 A orless” and “gusset length of 100 mm or less”■Development of a durability design method that reflects the difference in reliability of quality
To clarify the deterioration mechanismof a bridge in a severe salt damage
environment, we obtained the initialphysical property values of theconcrete of the pier of Irabu Bridge
when it was built to conduct a longterm state observation.

7

Coring analysis is performed regularly incollaboration with the road administrators

Research and Development – Development of Seismic
Technology for Infrastructure with Enhanced Earthquake Resilience –In the earthquake of 2011 off the Pacific coast of Tohoku, a powerful tremor and a huge tsunami struck an
extensive area of the Pacific coast, from Hokkaido to the Kanto region, causing enormous damages. Now,
the large-scale earthquakes expected to hit the Nankai Trough and the Tokyo area pose imminent threats,demanding more resilience (i.e., becoming stronger and more flexible) against such potentially major
earthquakes.
This research is aimed at the development of countermeasure technologies to prepare for earthquakes of
unprecedented scales and the other combined disasters that follow. With these studies, we wish to devise amethod to evaluate the performance of earthquake-resistant road bridges, road earthwork structures, androad /river structures, and develop and upgrade earthquake-resistant technologies. Ultimately, we hope thatthe practical application of the developed technologies and proposals to apply these to standards andbusinesses contribute to building a resilient society that can minimize the damage to its infrastructure andquickly restore its functions in the event of major earthquakes.

Resilience Technology of Road bridges against Excessive External ForceWith the objective of establishing the concept of a structurethat prevents fatal damages as much as possible and caneasily recover its functions, even in the event of an actionthat exceeds its design earthquake motion, we are studying
a method to design the damage scenario of bridges.
By assigning different strength levels to the bridge members
to control the order they are damaged, the damage form of
the entire bridge system changed and the seismic horizontal
coefficient at which the bridge collapses improved. With this,we confirmed the possibility of reducing the chances of abridge to collapse.
③

Stiffening beams
damaged
①

②

④
Arch
⑥ribs damaged

Relation between horizontal displacement
and horizontal seismic coefficient
Stiffening beams
damaged①⑤

Damage dgree
Small
Large

③

Arch ribs damaged②
Bearings
damaged ④(Damaged right after the design
horizontal seismic coefficient)

Damage state of the main member immediately before the bridge collapsed(left: with reinforced bearings; right: with bearings damaged in advance)

Research on Seismic Performance Evaluation Technology and Earthquake-ResistantReinforcement Technology of Entire Bridge System including Soil and Foundation■Countermeasures for Fluidization on Liquefied GroundWe are studying the countermeasures for fluidization
on liquefied ground through a world-class experimentusing E-Defense in collaboration with the National
Research Institute for Earth Science and Disaster
Resilience (NIED), as well as through a collaborative
research with the Tokyo Institute of Technology(Tokyo Tech) and the Japanese Association for SteelPipe Piles (JASPP). This is one of our initiatives tofurther improve our seismic performance evaluation
methods and earthquake-resistant countermeasuretechnologies for bridge foundation.

Experiment using E-Defense to develop
earthquake-resistant reinforcement
technology for bridges on liquefied soil

8

Research and Development– Specifications and Performance Standards –Contribution to the 2017 Specifications for highway bridges
The “Specification for highway bridges and its commentary” (by Japan Road Association) was revised in2017. In the revised Road Bridges Specifications, partial safety factor design method was adopted to clarify
the relation between the action and resistance assumed in the design, as well as the meaning of the safetymargins. In the past, CAESAR engaged in the research on variation in material strength, which is considereda premise for design, as well as the variation in the formula of load-bearing capacity (e.g., the shear bearing
capacity of concrete members). Both are required in to provide partial safety factor in the specification. We
also studied the influence of uncertainty of the soil reaction coefficient in the calculation of the response andbearing capacity of pile foundation and researched the performance evaluation of new materials, such as thehigh-strength bolt S14T. The revised Road Bridges Specifications also specifies partial coefficients thatconsider these analysis results, as well as new inspection standards for a few new materials.
○Consideration of repair reinforcement

Spare holes for replacement
or addition of cables

Difficulty in installing additional cables○Improved inspection space
Inspection
space

Moreover, based on the results andexpertise accumulated from planned
inspections across the country, theSpecifications determines that structuraldesigns should, to the extent possible,
avoid parts that are difficult to beinspected and repaired/reinforced. It also
states that the method of renewal andrepair reinforcement needs to be studiedin advance, and that the structures should
be designed to reduce uncertainty indesign such as local stress concentrations
and stagnant water.

Workspace
Inspection
space provided

No inspection space provided
Inspection and renewal of superstructures made easier

Horizontal load at sliding force action position ／ sliding force

Furthermore, CAESAR’s research results and the knowledge obtained with response to the 2011
earthquake off the Pacific coast of Tohoku and Kumamoto earthquake were applied to the specifications.
• We analyzed the mechanism of the damages caused by the tsunami due to the 2011 earthquake off the
Pacific coast of Tohoku region and the ground deformation or the slope collapse due to the Kumamoto
earthquake. Moreover, we proposed restoration methods that considers these events.
• We analyzed the mechanism of bridges with rocking pier that fell and suggested to stop using such an
unstable structure.
multi column groups-typebored deep foundation

column type bored
deep foundation△：yield load□：ultimate loada column group-type bored
deep foundation
multicolumn group-type
複数列組杭深礎基礎
bored deep foundation
Earthすべりにpressure causedby the sliding force

よる土圧

bearing
stratum
支持層

columntype bored deep
柱状体深礎基礎
foundationa column
group-type bored
単列組杭深礎基礎
deep foundation

Earthpressure caused
すべりにby the sliding force

Earthすべりにpressure causedby the sliding force

bearing
stratum
支持層

bearing
stratum
支持層

よる土圧

よる土圧

Horizontal displacement at sliding force action position （mm）

9

Analysis of the mechanism of damages causedby soil deformation

Hypothetical mechanism of collapse of a bridgewith rocking bridge piers

Dissemination and exchange of information– Lectures –With the objective of offering information about road bridge maintenance as well as a place for engineers tointeract, we hold our “CAESAR Lecture” once a year. This program consists of pertinent keynote speeches
and lectures from a wide range of professionals, such as professors involved in the maintenance of local
road bridges, road administrators of the state and local governments, road companies, and private groups.
The lecture is attended by over 400 people every
year (with a total of 4,130 attendees until the 10thassembly), including road administrators andprivate groups involved in the design,
construction, and maintenance of bridges, aswell as professionals from different fields
including materials, telecommunications, andnondestructive testing. After each edition of theevent, we receive many positive comments fromparticipants, saying that the lectures weremeaningful, useful in their workplace, and thatthey would like to participate again.

Picture of the 10th assembly of CAESAR lecture

Dissemination and exchange of information– International Activity –At CAESAR, besides the dissemination of Japanese technology abroad, we promote activities such as
information exchange and research cooperation on technical issues shared by research institutions androad administrators overseas. In the event of earthquakes and other disasters in other countries, we
conduct field examination and provide restoration support as needed.
When an earthquake struck Chile in 2010, CAESAR sent specialists to the affected area to examine thedamaged bridges and introduce Japan’s seismic design criteria to the technicians of the Chilean
government. In July of the same year, the country formulated its provisional criteria, which included some ofthe seismic technologies developed in Japan. In addition, from 2014, a technical cooperation that supports
the permanent revision of the seismic design criteria was coordinated by JICA, with CAESAR providing
technical support based on JICA’s requests. During this partnership, Japanese and Chilean technicians
exchanged opinions about the seismic design criteria on site, and TV conferences between Japan and Chile
were held for Q&A sessions and discussions with the Chilean technicians that had been sent to Japan. In
2017, the Chilean seismic design criteria for bridges were revised. The new criteria included a few
Japanese technologies, such as the liquefaction prediction method and the bridge unseating prevention
system. Later, not only did the PWRI receive a letter of appreciation from the Chilean Ministry of Public
Works but it was also cited in the preface of the seismic design criteria the cooperation of the institutions
that sent specialists to provide on-site support.

These criteria were revised basedon the precious knowledge andadvicereceivedfromthespecialists of MLIT, NILIM, and
PWRI, mediated by JICA.

Field survey after the earthquake in Chile

Cover of the new bridge seismic criteria

Preface10Places for Information Exchange– International Activities –CAESAR’s activities in the United States and Japan Conference on theDevelopment and Utilization of Natural Resources (UJNR)
UJNR, a US-Japan government meeting, was established for the two countries to learn as much as possible
about the effective use and maintenance of the natural resources around the world, as well as solutions forproblems concerning the human living environment through a partnership.
Considering that both Japan and the United States are countries that suffer damages from earthquakes,
strong winds, high tides, and tsunamis, the UJNR founded a special committee called Wind and EarthquakeResistant Structures Special Committee. It was established to enable professionals of the area to apply the
results of their development research to design methods of wind- and earthquake-resistant structures andexchange ideas.
In addition, CAESAR is responsible for the office of the Working Group G: Transit System, one of the working
groups of the Wind and Earthquake-Resistant Structures Special Committee. As part of its activities, so far,
we have held bridge workshops and exchanged information with governmental institutions, such as theFederal Highway Administration (FHWA) and state transit authorities, to establish partnerships.
In July 2018, we held a Japan-US bridge workshop at the California Department of Transportation as anopportunity to discuss issues concerning road bridges.
In this workshop, both countries explained the status of the respective technical standards for bridges, andthen discussed four topics (Topic 1: Rehabilitation and Retrofitting for Enhanced Durability and Preservation,
Topic 2: Bridge Instrumentation and Health Monitoring, Topic 3: Guidelines and Use of Refined Numerical
Calculations for Design and Bridge Assessment, Topic 4: Innovative Materials for Bridges Design andConstruction). The discussions were significant, and there was a consensus on the importance of continuing
to exchange ideas in the future.

11

California Department of Transportation

Topic leader’s proceeding and presentation

Q&A session

Study tour (observation of cable-stayed bridge construction site)Organization
PWRI
Tsukuba Central Research Institute
Civil Engineering Research Institute for Cold Region
ICHARM, International Center for Water Hazard and Risk
management, under the auspices of UNESCOCAESAR, Center for Advanced Engineering Structural
Assessment and Research
Bridges and Structures Research Group
Director of Bridges and Structures Research(Acting Director of CAESAR)
Chief Researchers (Principal Investigators)- Management System and Substructures- Structural Assessment and Superstructures- Rehabilitation and Earthquake Engineering- Inspection Technology and Concrete Structures
Ad hoc Specialized Unit
Director for Earthquake Engineering

iMaRRC, Innovative Materials and Resources Research Center
CAESAR develops technologies and research on matters concerning the maintenance of bridges andprevention and mitigation of earthquake damage to civil structures, as well as concrete structures that
include superstructures and substructures of bridges. It is a comprehensive organization formed bytechnicians and researchers specialized in a holistic maintenance system that integrates the repair,soundness prediction evaluation, inspection technology, design and construction, and seismic design ofbridges. In addition, if the road administrator requests support for an urgent issue that requires anintensive and high-level technical collaboration, we can flexibly form a temporary specialized unit to workon it on a full-time basis.
If a research concerns the properties of materials that contain earth, painting, or is mainly related to cold
weather-specific phenomena, we follow CAESAR’s plans and coordination and try to solve the issue
through collaborative research with concurrent members from the Tsukuba Central Research Institute andthe Civil Engineering Research Institute for Cold Region, as well as cooperation with related fields.
As of August 1st, 2018
Enrolled researchers
22 in-house, 2 specialized, and 16 visiting researchers
24 research tasks and 15 collaborative researches with industries, government, and academia
Main full-scale experiment facilities
Removed member storage facility for clinical research, wheel-load running test machine, 1,000 kN fatigue
test machine, member seismic strength experiment facility, large-scale structure repeated loading test
device, structure repeated loading device, 30 MN large-scale structural member all-purpose test machine12

Contact
Based on an abundant wealth of knowledge accumulated over the years, CAESAR provides technicalguidance and support to road administrators on the design, seismic reinforcement, and damages (saltdamage and alkali-aggregate reaction, fatigue, and others) of road structures. Moreover, as a research unit
engaged in the design, seismic reinforcement, and damages of road structures, we conduct collaborative
research with the industry and academia as necessary. For more information, please contact us at thedetails below:Roadadministrator
Technical
guidance

High technology
case

CAESAR
Privatesectors

Joint andcollaborative
research

Academic
sectors

National Research and Development Agency
Public Works Research InstituteCenter for Advanced Engineering Structural
Assessment and Research
Address: 1-6 Minamihara, Tsukuba, Ibaraki,
Japan 305-8516
TEL: 029-879-6773
Email: caesar@pwri.go.jp
URL: http://www.pwri.go.jp/caesar/index-j.html

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