2022 Fiscal Year Final Research Report

Studies on Structural Analysis and Slab Thickness Design Methods for Long-Life Concrete Pavement in consideration of Differential Settlement of Soft Ground

Research Project

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Project/Area Number	18K04301
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Multi-year Fund
Section	一般
Review Section	Basic Section 22010:Civil engineering material, execution and construction management-related
Research Institution	Hiroshima University
Principal Investigator	Sato Ryoichi 広島大学, 先進理工系科学研究科(工), 名誉教授 (20016702)
Co-Investigator(Kenkyū-buntansha)	半井健一郎広島大学, 先進理工系科学研究科(工), 教授 (10359656) 小川由布子広島大学, 先進理工系科学研究科(工), 助教 (30624564)
Project Period (FY)	2018-04-01 – 2023-03-31
Keywords	Differential settlement / CRCP / Gap / shear transfer / Creep
Outline of Final Research Achievements	The effect of differential settlement on the stress of CRCP was investigated numerically from viewpoint of presence of absence of contact of slab and subbase, gap depth between slab and As intermediate layer, shear transfer mechanism of transverse crack. The presence of absence of the contact was judged by means of incremental theory. The shear transfer performance was predominant when coarse aggregates engaged with each other. The gap depth below the slab and was measured to be 0.5mm on site. The levels of loads, temperature differences between top and bottom surface of slab and running position reached 3120 in total. Calculation time using 3D-FEM needed over 30,000 hours which was difficult to accomplish all of case. To solve this problem, decreasing load levels, calculation numbers reduced to 100. Furthermore, In order to contribute to rationalizing calculation of fatigue degree, the distribution of stress for fatigue degree was shown.
Free Research Field	土木材料
Academic Significance and Societal Importance of the Research Achievements	不同沈下の影響を受けるCRC版の応力解析は版と路盤の接地・剥離、横ひび割れ部のせん断伝達等高い非線形性を有する。この種の問題は埋め立て空港で検討されたが、基本的に板ばねモデルであった。そのため版と路盤とのたわみの適合条件が崩れ、版のたわみが路盤のそれより大きくなるといった矛盾があった。また、横ひび割れ部のせん断伝達が線形ばねでモデル化されひび割れ幅の影響を考慮できないせん断伝達機構を忠実に表すものではなかった。本研究はこの問題点を克服するもので、上記ばねモデルで設計された埋立て空港のCRCPの再評価を行い、その合理性を示した。これは実務に供するものでその学術的、社会的意義は大きい。