| 講演要旨(和文) | | PS速度検層は，地盤の工学的評価の指標となるP波S波速度層構造を直接測定することが可能な，土木物理探査分野で生き残った数少ない検層技術の一つである．提供する1D速度層構造の信頼性を高めるには，まず測定品質に関わる技術的課題を整理し，各々の課題に対する技術的現況と解決の方向を明らかにする必要がある．本報告ではPS速度検層をめぐる問題を振源，経路，孔状態および測定ツールに分けて整理するとともに，各種S波振源の比較測定結果とSH波の効率的発生に係る技術的要点を述べる． |
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| | 講演要旨(英文) | | P- and S-wave velocity logging is one of the geophysical methods which have remained in geotechnical engineering field as the in-situ measurement method for determining P- and S-wave velocity structure of the near surfaces. Regretfully, state of the measurement techniques seems to still be in chaotic situation in Japan and to waste effort by trying to standardize the techniques by non-specialists. Meanwhile, geotechnical engineers have requested geophysicists to provide more accurate and reliable information of near-surface P- and S-wave velocity structure. To do this, it is essential to review the state of the arts of PS logging techniques and clarify the practical problems to be settled. In this paper, the author focus on S-wave velocity logging, and first classifies the problems into sources, tools, and utilization of S-wave velocity data. Next, technical essences on the generation of SH-waves are discussed. |
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