[H-DS07] 地すべりおよび関連現象

[HDS07-P07] 令和６年能登半島地震時に発生した内灘町の液状化と地すべり現象について

*王 功輝¹、古谷 元²、林 宏一¹、土井 一生¹、松澤 真¹、闫 孔明¹ (1.京都大学防災研究所、2.富山県立大学)

キーワード：2024年能登半島地震、地すべり、液状化、せん断挙動、物理探査

During the 2024 Noto Peninsula Earthquake, different types of geohazards occurred on the wide area of Kanazawa, Toyama and Niigata Prefecture. Among these geohazards, liquefaction and lateral spreading phenomena occurring on Uchinada area were extremely severe, resulting great damage to local properties, such as landslides with blocking of drainage river channel, lateral moving of ground with houses, titling of main roads, on wide area. To unravel the reasons for these phenomena, we conducted multiple types of geophysical surveys (including MASW, ERT) on the ground of severely damaged areas, conducted cone-penetration tests. We sampled sandy soils from the liquefied sands, and conducted undrained static and dynamic loading tests on the samples. The MASW survey results showed that the soil layers have low Vs value (around???), while ERT survey results indicate that the soil layers have shallow ground water. Results of undrained ring shear tests reveal that the sands could be liquefied subjected to the strong shaking similar as that observed in the main shock. We further analyzed the variation of geohazard potential with local development of soil lands.