Experimental Studies on Deformation Evaluation of Steel Wire Mesh for Rational Design of Gabion Structure - Basic Research for Constructing the Theoretical System of Gabion -
蛇龍を用いた構造物の利点は,簡易な構造かつ工費・工期ともに優れている点であり,国内外で多種 多様に用いられている.過去の地震被害調査においても,変形は許容しているものの,崩壊に至らないケースが多く確認され,中詰め材である石に対する金網の拘束効果が高いことが実証されている.しかし,蛇龍の設計・施工は経験に基づいたものであり,設計手法が未整備であることから,日本国内においては,積極的な利活用や恒久的な構造物としての建設に至ってないのが現状である.そこで,蛇龍を用いた構造物の設計手法構築にあたり,まずは基礎に立ち返り,金網そのものの変形メカニズムを詳細に把握する必要があると考えた.本研究では,形状の異なる金網の引張試験を実施し,その強度および変形特性の把握と数値解析を試みた.引張試験から,金網形状と引張方向により変形特性が異なり,金網の節点と引張が作用する方向が重要であること,および梁要素を用いた FEM 数値解析により試験結果の再現が可能であることを示した.
Gabion structures are used in a variety of ways in Japan and around the world because they allow for the creation of simple structures at highly reasonable construction costs and completion periods. Previous earthquake damage surveys have shown that, in many cases, gabion structures did not collapse even though deformation was allowed, and have demonstrated that the wire mesh used in their construction has a high confinement effect on the stones filling the gabion. Despite this, gabions have not been actively utilized, nor have they been used to construct permanent structures in Japan because the design and construction of such structures are based on experience, and a standardized design method has not been developed. Hence, in order to facilitate development a design method for
gabion-based structures, we must first go back to the basics and establish a detailed explanation of the wire mesh deformation mechanism of such structures. In this study, we performed tensile tests on wire meshes of different shapes in order to determine their strength and deformation characteristics and then conducted numerical analyses using the results obtained. The tensile tests revealed that deformation characteristics differed depending on the mesh shape and tensile direction. We also showed that the direction in which the tension acts and the mesh nodes are important, and that the test results could be reproduced via numerical analysis with the finite element method by using beam elements.
雑誌名
防災科学技術研究所 研究資料
雑誌名(英)
Technical Note of the National Research Institute for Earth Science and Disaster Resilience