Volume 6, Number 4, December 2008

CAESAR’S ANATOMICAL/AUTOPSY SURVEY FOR OLDER/DAMAGED HIGHWAY
BRIDGESCAESAR (Center for Advanced Engineering Structural Assessment and Research), one of PWRI’s research
institutions located in Tsukuba, Japan, is a national center of excellence in research and technical support for highway
administrators in performing design, construction, maintenance, and disaster mitigation for highway bridges. The
establishment of CAESAR on 1 April 2008 was reported at the 40th UJNR joint Panel meeting held in Gaithersburg,Maryland, U.S., May 2008 and the contribution by CAESAR was welcomed in the Panel Meeting Resolutions.
As Mr. Matsuo, Research Coordinator for earthquake engineering, PWRI and CAESAR, reported during the Panel
Meeting, CAESAR’s mission addresses highly sophisticated issues for which relevant diagnosis and prognosis
technique, assessment method, or corrective method has not been generally understood. CAESAR, working withhighway administrators, tackle anatomic/autopsy survey of older bridges that will be decommissioned to improve theirdiagnosis/prognosis techniques and to measure, test, and simulate structural components and systems. That’s whatCAESAR calls scientific trials.
Mr. Murakoshi, Chief Researcher for Structural Assessment and Superstructures of CAESAR, leads several projects
in autopsy survey for bridges that will be decommissioned. One of the on-going projects is the autopsy study using
Asahi Bridge (see photo 1). The bridge is three-span continuous steel I-girder bridge located in Hokkaido. This work is
jointly performed with Mr. Ishikawa, serving concurrently as Chief Research of CAESAR from CERI (Civil Engineering
Research Institute for Cold Region) and his CERI team. The Asahi Bridge was built in 1953 and decommissioned inDecember 2008 because of functionally obsolesce. A truck load test, vibration test, and non-destructive evaluations fordecks were conducted on-site from October 2008 to December 2008 and a series of fatigue load test, of a part of thedeck plate and numerical simulations for the bridge and deck behavior, will be carried out in the near future.
In addition, another key project involved performing an autopsy on a large-span steel truss and girder bridge with total
length of 1,200 m (see photo 2). The annual average daytime traffic is 20,000 vehicles; 10% are designated as heavyvehicles. The bridge was open in 1962 and will be decommissioned in 2009 because of its deterioration – corrosion,
fatigue, and lack of adequate seismic performance. Many large-parts of the bridge were sampled and transported to
CAESAR’s large-scale structural test laboratories, followed by load tests and non-destructive evaluations, etc. that wereperformed on-site. Researchers conducted a visual bridge inspection, reviewed the history of earlier rehabilitation
works, and started performing finite element models. They will analyze many issues to improve the inspection
technique to identify structural deficiencies and perform prediction technique to estimate remaining strength ofdeteriorated critical structural components during 2009 and 2010. Mr. Kimura, Chief Researcher for Inspection
Technology and Concrete Structures, CAESAR, is preparing other autopsy projects for concrete structures.
In addition to countering Japan’s decaying highway bridges, CAESAR is working hard to facilitating a more disaster
resilient nation. As the collapse of bridges in the 14 June 2008 Iwate-Miyagi Nairiku Earthquake, Dr. Unjoh, CESAR’sChief Researcher for rehabilitation and earthquake engineering and Dr. Sakai, CESAR’s Senior Researcher were partof the technology Scan Team. The collapse of the Matsurube Oh-hashi Bridge was reported in the Panel’s newsletter,
Panel Update, Volume 6, Number 2, August 2008 and is in Photo 3 below. Dr. Nakatani, Chief Researcher for
management system and substructures, and his team are seeking effective seismic reinforcement measures for theMatsurube Oh-hashi Bridge collapse and for other existing bridges. Drs. Unjoh and Nakatani also are working intechnical committees involved in investigating the cause of the collapse of the Matsurube Oh-hashi Bridge andrecommending corrective measures for other bridges with similar damage during the earthquake.
CESAR findings will be shared during future Panel Meetings and during the Panel’s TC/G-hosted US-Japan Bridge
Engineering Workshops.
Contact. Dr. Masahiro Shirato, Senior Researcher, Bridges and Structures Research Group, CAESAR, PWRI,
shirato@pwri.go.jp

Asahi Bridge

Truck load test for vehicular
breaking forces

NDE for deterioration ofdeck plate

Photo 1. Autopsy survey usingAsahi Bridge in Hokkaido.

Photo 2. Alarge-span steel girder and truss bridge used in the autopsy survey and corrosion of its typical gusset plate.

Photo 3. Collapse of Matsurube Oh-hashi Bridge during the 2008 Iwate-Miyagi Nairiku Earthquake and emergency scan team by aspecial unit including CAESAR researchers.

24TH US-JAPAN T/C G BRIDGE ENGINEERING WORKSHOPTask Committee G (T/C G), Transportation Systems, hosted its 24th US-Japan Bridge Engineering Workshop during
22-24 September 2008, in Minneapolis, Minnesota. This Workshop is a continuation of a series of technicalinterchanges between the United States and Japan on topics related to bridge engineering. This 2008 Workshop
focused on seismic design/retrofit and maintenance. Forty-five people attended the workshop. The US delegation wasled by Dr. W. Phillip Yen (US-side T/C Chair), Federal Highway Administration, Department of Transportation(FHWA/DOT) and the Japanese delegation was led by Mr. Atsushi Yoshioka (Japan-side T/C Chair), CAESAR(Center for Advanced Engineering Structural Assessment and Research), PWRI. The T/C chairs organized theirdelegations to facilitate an open exchange of ideas and to encourage discussion. The delegations consisted of FHWA
researchers, State DOT bridge engineers, CAESAR researchers, NILIM researchers (National Institute for Land andInfrastructure Management of the Ministry of Land, Infrastructure and Transport, Japan) and associated academic
researchers and industrial bridge engineers.
The 2 ½ day workshop featured nine technical sessions with 42 presentations and two breakout sessions that

addressed seismic issues and maintenance. Critical issues included the practice of bridge maintenance, seismic
retrofit design in the US, code requirements on the post-earthquake serviceability, and manuals on the postearthquake emergency recovery of damaged bridges after a severe earthquake in Japan. In addition, aninterdisciplinary topic on the maintenance and durability of seismic retrofit materials was raised. The workshop closedwith the Resolutions that the 25th Workshop will be held in Japan in the fall of 2009. The past Workshop agenda andtechnical papers are available at http://www.pwri.go.jp/eng/ujnr/tc.htm. The 24th Workshop agenda and technicalpapers will be soon uploaded to the web site.
Following the Workshop, the delegation members participated in three-day Bridge Technical Site Visits where small
technical meetings were held at particular bridge project sites with representative engineers and researchers.
Minneapolis experienced the I-35 W bridge collapse on 1August 2007. The delegation attended the Minnesota DOT
and the bridge site to discuss the collapse, design, and construction of the new bridge and methods to improve bridge
engineering. The new bridge construction was completed within a year of the collapse and included many monitoring
sensors that are arranged inside the bridge. The delegation also visited the Multi-Axial Subassemblage Testing(MAST)-NEES Facility, University of Minnesota to discuss their experimental studies. The delegation then moved toSan Francisco, California. On 26 September they reviewed projects on seismic retrofit and replacement of large spanbridges around the San Francisco Bay. There was active discussions on the design of RC towers, retrofit of truss
bridges, and durability of seismic retrofit devices.
Contacts. Japan Side Organizer - Dr. Masahiro Shirato, Center for Advanced Engineering Structural Assessment andResearch (CAESAR), Public Works Research Institute (PWRI), shirato@pwri.go.jp and US Side Organizer Professor David H. Sanders, Professor of Civil and Environmental Engineering at the University of Nevada, Reno,sanders@unr.edu

Photo 4. Group Photo of the Task Committee G Delegation