【特集報文】 |
既設道路橋の現状と求められる技術開発
Conditions of Existing Road Bridges and the Needs for Technologies to Enhance Bridge Durability |
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玉越隆史・加藤 豊
Takashi TAMAKOSHI,Yutaka KATO |
<抄録> 道路橋の定期点検結果の分析や不具合事例の対応等に基づき、既設道路橋にどのような不具合が生じているかを整理するとともに、維持管理の実状も踏まえた耐久性の信頼性向上のために求められる技術と国土技術政策総合研究所の取り組みの例を紹介する。
In this report, we classify types of problems detected in existing road bridges, based on the analysis of regular inspection results and responses to problems found. We also introduce technologies designed to cope with the current situation of maintenance and management and capable of providing more reliable durability, and explain the efforts by the National Institute of Land and Infrastructure Management towards the realization of such technologies. |
<キーワード> 耐久性、維持管理性、劣化リスク、阻害要因
Keywords: durability, maintenance and management, deterioration risk, interrupting factor |
【特集報文】 |
既設道路橋における鋼部材の腐食と技術開発
Development of Maintenance Technology for Mitigating Corrosion Issues on Steel Members in Highway Bridges |
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村越 潤・田中良樹・高橋 実
Jun MURAKOSHI,Yoshiki TANAKA,Minoru TAKAHASHI |
<抄録> 安全の確保と社会資本ストックの有効活用の観点で、腐食してしまった鋼部材を発見した後の適切な対応が重要である。しかし、腐食した鋼部材の性能評価や補修・補強には多くの課題があり、さまざまな技術開発が必要である。本文では、道路橋における鋼部材の腐食劣化の現状と課題を示すとともに、土木研究所CAESARの取組みを紹介する。
To ensure safety and effectively use existing social infrastructure, it is important to take appropriate measures when corroded steelmembers are found in such structures. In reality, many issues have been addressed in evaluating their performance and carrying out repair and reinforcement works, and a wide range of technological development is necessary to work out such problems. In this report,we present actual cases and issues of corrosion found in the steel members of road bridges, and introduce the efforts to solve the problems by the Center for Advanced Engineering Structural Assessment and Research (CAESAR) of the Public Works Research Institute of Japan. |
<キーワード> 腐食、断面欠損、破断、補修・補強、凍結防止剤、腐食環境改善
Keywords: corrosion, partial loss of area, rupture, repair and reinforcement, antifreezing agent, improvement of corrosive environment |
【特集報文】 |
既設道路橋における鋼部材の疲労と技術開発
Recent Research and Development on Maintenance Technology for Fatigue on Steel Highway Bridges |
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村越 潤・高橋 実・佐藤 歩
Jun MURAKOSHI,Minoru TAKAHASHI,Ayumu SATO |
<抄録> 近年、鋼橋において、鋼部材の深刻な劣化損傷や不具合の事例が報告されており、今後の増加が懸念される。本稿では、鋼橋の代表的な劣化形態であり、3大損傷の一つとされている疲労による損傷の現状と課題を述べるとともに、これまでCAESARで実施してきた臨床研究等による研究開発の取組み事例を紹介する。
In recent years, serious deterioration and other problems have been reported with steel members used in steel bridges, and such problems are expected to increase in the future. In this report, we explain the current situation and issues on fatigue damage, which is typical deterioration and one of the three major types of damage found in steel bridges. We also report cases of research and development in this area, including a clinical type, conducted by the Center for Advanced Engineering Structural Assessment and Research (CAESAR) of the Public Works Research Institute of Japan. |
<キーワード> 道路橋、鋼部材、疲労、き裂、維持管理、非破壊調査技術、補修補強
Keywords: road bridge, steel member, fatigue, crack, maintenance and management, non destructive examination technology, repair and reinforcement |
【特集報文】 |
既設橋コンクリート部材の塩害と技術開発
Chloride Attack on Existing Bridge Concrete Members and Development of Prevention Technology |
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石田雅博・宇佐美 惣・大島義信・吉田英二
Masahiro ISHIDA,Osamu USAMI,Yoshinobu OOSHIMA,Eiji YOSHIDA |
<抄録> 土木研究所CAESARでは劣化損傷の生じた実橋の状態を把握するため、撤去された橋梁について非破壊検査や載荷試験、解体調査を行っており、より効率的な検査技術や評価手法の確立に向けて調査研究を進めている。本文では、既設橋コンクリート部材の塩害対策の現状と課題について概説するとともに、必要となる技術開発についてCAESARの取り組みを紹介する。
The Center for Advanced Engineering Structural Assessment and Research (CAESAR) of the Public Works Research Institute (PWRI) of Japan conducts investigation and research to develop more effective inspection technologies and assessment methods based on analysis on the conditions of deterioration in actual bridges through non destructive examination, loading test, and disassembly investigation on dismounted bridges. In this report, we outline the current status and issues concerning measures for preventing chloride attack on concrete members of existing bridges. We also present technological developments led by PWRI-CAESAR to achieve such prevention measures. |
<キーワード> 塩害、維持管理、PC橋梁、耐荷力評価、非破壊検査技術(高出力X線透過法)
Keywords: chloride attack, maintenance and management, PC bridge, load bearing capacity, non destructive examination technology (highpower X-ray transmission method) |
【特集報文】 |
既設橋コンクリート部材のASRと技術開発
ASR Deterioration of Concrete Members in Existing Bridges and Development of Coping Measures |
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石田雅博・七澤利明・古賀裕久
Masahiro ISHIDA,Toshiaki NANAZAWA,Hirohisa KOGA |
<抄録> アルカリ骨材反応により劣化した既設橋コンクリート部材の維持管理に関する現状と対策の動向を概説するとともに、必要となる技術開発と土木研究所での取組み(フーチング補強等)、現場での対応事例(既設橋の診断及び補修事例等)について紹介する。
In this article, we outline the current practice of maintenance and management of existing bridge concrete members deteriorated due to alkali-aggregate reaction (ASR), and review the recent trend of coping measures for this type of deterioration. We also present related technological developments, maintenance efforts such as footing reinforcement by the Public Works Research Institute of Japan, and actual cases in which diagnosis and repair were conducted for existing bridges. |
<キーワード> アルカリ骨材反応(ASR)、フーチング、暴露試験、診断、補修・補強
Keywords: alkali-aggregate reaction, footing, exposure test, diagnosis, repair and reinforcement |
【特集報文】 |
道路橋基礎の地震時挙動の評価と耐震対策技術の開発
Recent Research Activities on Seismic Evaluation and Retrofit of Existing Foundations for Bridges |
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星隈順一・七澤利明
Jun-ichi HOSHIKUMA,Toshiaki NANAZAWA |
<抄録> 本稿では、より実際に近い基礎の地震時挙動、より実際に近い基礎の耐力・変形特性を評価できるようにしていくため、現在、土木研究所で取り組んでいる液状化地盤における基礎の地震時挙動の評価の高度化と耐震対策に向けた取組み、既設基礎の地震時限界状態の評価の高度化に向けた取組みの最新情報を紹介する。
We conduct research and development to achieve realistic evaluation of the seismic behavior and the resistance and deformation capacity of bridge foundations. In this report, we present the latest information on the current efforts by the Public Works Research Institute to improve the evaluation of the seismic behavior of bridge foundations built on liquefiable ground and to implement seismic retrofitting for such structures, as well as to upgrade the evaluation of seismic limit state of existing bridge foundations. |
<キーワード> 道路橋基礎、地震時挙動、地震時限界状態、耐震対策、地盤調査
Keywords: road bridge foundation, seismic behavior, seismic limit state, seismic retrofitting, ground investigation |
【現地レポート】 |
道路橋の老朽化対策と技術的課題への対応
Countermeasures for Aging Road Bridges and Identification of Technical Problems |
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森 浩樹・小澤慶之
Hiroki MORI,Yoshiyuki OZAWA |
<抄録> 道路構造物の維持管理に関わる老朽化対策の実施にあたって、本格的なメンテナンスサイクルの始動から2年目を終えた。関東地方整備局における老朽化対策への取り組みについて紹介するとともに、この結果、浮かび上がった現場で求められている技術的課題等について示す。
Two years has passed since the full cycle of maintenance for aging road bridges started as part of the maintenance and management of road structures. In this report, we describe the efforts by the Kanto Regional Development Bureau of Japan in the implementation of measures for aging road bridges and present technical and other issues found in applying such measures to actual cases. |
<キーワード> 老朽化対策、道路メンテナンス会議、定期点検、予防保全、鋼床版疲労き裂
Keywords: measures for aging infrastructure, road maintenance meeting, regular inspection, prevention and maintenance, fatigue crack in steel deck plate |
【一般報文】 |
地震により被災した橋梁の被災メカニズムの推定
Analysis of a Damage Mechanism affecting Bridges Damaged during the Tohoku Earthquake |
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田辺晶規・河野哲也・七澤利明・谷本俊輔
Akinori TANABE,Tetsuya KOUNO,Toshiaki NANAZAWA,Shunsuke TANIMOTO |
<抄録> 東北地方太平洋沖地震において、比較的類似した地盤条件等の2つの橋台杭基礎の挙動を静的及び動的解析で確認を行った。その結果、一部で被災状況と乖離した解析結果が見られたものの、杭基礎は地盤の振動変位の影響が大きく、杭頭部付近で大きな地盤の振動変位が生じる条件で既製RC杭は注意が必要であることが確認された。
Static and dynamic analyses were conducted to examine the behavior of two abutment pile foundations, which had similar ground conditions, at the time of the 2011 off the Pacific coast of Tohoku Earthquake. Though some of the results differed from the actual damage of the foundations, the analyses confirmed that pile foundations can be affected by ground vibration displacement to a great degree, and that due care should be taken for the use of precast RC piles when large ground vibration displacement is anticipated around the pile heads. |
<キーワード> 東北地方太平洋沖地震、静的解析、動的解析、地盤の振動変位、鋼管杭、既製RC杭
Keywords: The 2011 off the Pacific coast of Tohoku Earthquake, static analysis, dynamic analysis, ground vibration displacement, steel pipe pile, precast RC pile |
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伊藤弘之・山本 晶・湯浅直美
Hiroyuki ITO,Akira YAMAMOTO,Naomi YUASA |
<抄録> 平成27年9月10日に、常総市鬼怒川左岸において溢水、決壊が発生した。氾濫した河川水は氾濫地点近傍の家屋を流失等させた他、10km以上も下流にある中心市街地に達した後、水深の大きな浸水域を形成した。これにより多くの屋内避難者の孤立化や、水道・下水道等ライフラインの被害等が生じた。国総研水害研究室では、これら被害発生状況について調査を行った結果について、中間報告を行う。
On September 10, 2015, an overflow and levee breach occurred on the left bank of the Kinu River in Joso City. The floodwaters from the river washed out houses near the breach point, reached the downtown area located over 10 km downstream, and finally formed a huge inundation area with a high depth, which stranded many residents who chose to stay home for safety and caused damage to lifeline utilities such as water and sewage systems. This report presents preliminary results from the investigation on damage caused during the flood by the Flood Disaster Prevention Division of the National Institute for Land and Infrastructure Management of Japan. |
<キーワード> 常総市、浸水、孤立被害、ライフライン、避難
Keywords: Joso City, inundation, isolation, lifeline utility, evacuation |
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吉村仁志・松田奈緒子・牧野浩志
Hitoshi YOSHIMURA,Naoko MATSUDA,Hiroshi MAKINO |
<抄録> H22年度からITSスポットが設置され、ETC2.0情報提供サービスが開始された。国総研ではH23年度よりETC2.0情報の効果や課題を把握するため、モニタアンケート調査を毎年実施してきた。本稿では、利用期間3年以上となるモニタへのアンケート結果および、パス解析を用いてサービス満足度に対する影響要因の分析結果を報告する。
The Electric Toll Collection (ETC) 2.0 information delivery service has been in operation since 2010, when Intelligent Transport Systems (ITS) spots were installed in certain places around Japan. The National Institute for Land and Infrastructure Management of Japan has annually conducted questionnaire surveys for selected respondents since 2011 to analyze the effect and issues of ETC2.0 information. In this report, we present the results from the questionnaire administered to those who had used the service for three years or longer and the results from pass analysis on factors affecting user satisfaction. |
<キーワード> ETC2.0、情報提供、長期利用者、ユーザー評価、パス解析
Keywords: ETC2.0, information provision, long-term user, user evaluation, pass analysis |
【土研センター】 |
鹿児島県における鋼橋の塗替え塗装の合理化
Rationalization of the Steel Bridge Recoating System in Kagoshima Prefecture |
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中野正則・安波博道・五島孝行・中島和俊・内藤哉良
Masanori NAKANO,Hiromichi YASUNAMI,Takayuki GOTO,Kazutoshi NAKASHIMA,Chikara NAITO |
<抄録> 鹿児島県が管理する鋼道路橋5橋を対象として、構造安全性を維持した上で1橋当たりの塗替え塗装費を大幅に縮減可能な“部分塗替え塗装”を取り入れた塗装設計を実施した。本報はこれら5橋の塗装設計事例の概要をとりまとめて報告するものである。
We applied coating design including partial recoating to five steel road bridges managed by Kagoshima Prefecture, Japan. The Partial Recoating System is expected to reduce the recoating cost per bridge dramatically while ensuring structural safety. In this report, we present an overview of the recoating designs for the five bridges. |
<キーワード> 塗替え塗装、部分塗装、塗装設計、健全性評価
Keywords: recoating, partial coating, coating design, integrity evaluation |
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