Evaluation of new liquefaction damage mechanism for pipelines buried above ground water level

2020 Fiscal Year Final Research Report

• Project/Area Number: 19K15088
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 22030:Geotechnical engineering-related
• Research Institution: Ehime University
• Principal Investigator: Ono Kohei 愛媛大学, 理工学研究科(工学系), 講師 (30804166)
• Project Period (FY): 2019-04-01 – 2021-03-31
• Keywords: 液状化 / パイプライン / 耐震

Outline of Final Research Achievements

This study focuses on the seismic displacement behaviors of a pipeline buried above the groundwater level. The purpose of the study is to verify the flotation of the buried pipe during liquefaction and following its settlement due to the volume compression of the liquefied sand layer by a series of centrifuge experiments. The vertical displacement mechanism of the buried pipe during liquefaction was investigated by controlling the groundwater level and applying horizontal one-dimensional excitation using a shaking table. The influence of the behavior of the upper unsaturated sand layer on the displacement of the buried pipe during the dissipation process of the pore pressure after liquefaction was also clarified.

Free Research Field

地盤工学

Academic Significance and Societal Importance of the Research Achievements

従来，地下水位以浅に埋設された管路は液状化対策の検討を必要としなかったが，近年，埋戻し土より下層が液状化したことに伴い浮上や不同沈下を起こす事例が相次いで報告されており，埋設管路の新たな液状化被害メカニズムの存在が浮き彫りとなっている。本研究課題は，遠心力場において原型スケールの応力状態を再現した振動模型実験を実施することで，上記の被害メカニズムの一端を明らかにしたものである。今後，より定量的な検討を進めていくことで，合理的な耐震設計手法の確立，および対策手法の充実が期待される。