| 講演要旨(和文) | | 舗装路の健全性の評価手法として，非破壊検査の適用が求められている．FWD（Falling Weight Diflectometer）がこの分野で主要な手法となっているが，その測定結果から弾性係数などの物性値を求める研究は続いている．筆者らは，舗装路の非破壊検査手法としての表面波探査の適用性を研究するために原位置探査を行った．圧電素子加速度計とジオフォンを受振器として使い，結果を比較した．探査の結果，Lamb波の０次非対称モード（A0モード）を解析すれば，舗装アスファルトの層厚と弾性波速度を推定するために，ジオフォンを使うことが有効であることがわかった．また，A0モード解析と遺伝的アルゴリズムによる正規モード解析を組み合わせることで，舗装表・基層だけでなく，路盤，路床および基礎地盤の性状がS波速度分布として把握できることを確認した．今後，本手法を実用化するために，更なる改良を行う予定である． |
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| | 講演要旨(英文) | | Nondestructive testing for assessment of paved road has been demanded. FWD (Falling Weight Diflectometer) is one of the main methods for this demand. However, FWD data analysis to determine the elastic modulus of a paved road is still under-development. The authors conducted a feasibility study utilizing the MASW (Multichannel Analysis of Surface Waves) as a nondestructive test method for paved roads. Piezoelectric accelerometers and geophones were employed as receivers and the obtained results were compared. As a result of the study, we determined that geophones are suitable to estimate thicknesses and elastic wave velocities of paved asphalt if the A0 mode of Lamb waves is to be interpreted. We also determined that combining both this A0 Lamb mode interpretation and Normal Mode Solution using a genetic algorithm (Hayashi, 2012) would be an appropriate analytical method to characterize not only pavement surface materials but also its underlying roadbed and foundation in terms of its shear wave velocity structures. Further studies will be carried out to improve the method so as to make it a practical technique. |
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