Liquefaction resistance of partly saturated sand located immediately beneath groundwater levels

位于地下水位以下的部分饱和砂的抗液化性

• 批准号: 12555144
• 负责人: TSUKAMOTO Yoshimichi
• 金额: $ 8.58万
• 依托单位: Tokyo University of Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-12555144/
• 关键词: Partial saturation; Sandy soil; Elastic wave velocities; Coefficients of pore water pressure; Soil liquefaction; Flow characteristics; Residual strength; 不飽和; 液状化強度; 弾性波速度; 繰返し三軸試験

The possibility of liquefaction occurrence has been conventionally evaluated by performing laboratory tests on fully saturated soil specimens, assuming that the soil layers beneath groundwater levels are fully saturated. However, according to insitu velocity profile measurements, the degree of saturation is found to reduce due to the inclusion of a small amount of air bubbles, and therefore P-wave velocities immediately beneath groundwater levels are lower than those measured in fully saturated soil layers far below the groundwater levels. This study is aimed at properly evaluating the liquefaction resistance and flow characteristics of partly saturated sand existing immediately below the groundwater levels. The triaxial test apparatus capable of measuring P-wave and S-wave velocities is developed. The relationships among the B-value, saturation ratio Sr and P-wave velocities are examined, in which the B-value and Sr are used to evaluate the degree of saturation in laboratory tests, and P-wave velocity is used to evaluate the degree of saturation insitu. Furthermore, in relation to the P-wave and S-wave velocities, the liquefaction resistance and flow characteristics of partly saturated sand are examined by performing undrained monotonic and cyclic triaxial tests.

液化发生的可能性通常通过对完全饱和的土壤样本进行实验室测试来评估，假设地下水位以下的土层完全饱和。然而，根据原位速度剖面测量，饱和度被发现减少，由于包含少量的气泡，因此，P波速度低于地下水水位以下的完全饱和的土层中测得的远低于地下水水位。本研究旨在正确评估地下水位以下部分饱和砂土的抗液化性和流动特性。研制了一种可同时测量纵、横波速度的三轴试验装置。研究了B值、饱和度Sr和纵波速度之间的关系，其中B值和Sr在室内试验中用于评价饱和度，纵波速度在现场用于评价饱和度。此外，相对于P波和S波速度，部分饱和砂土的抗液化和流动特性进行了不排水单调和循环三轴试验。

项目成果

Kamata, K., Ishihara, K. & Tsukamoto, Y., Nakazawa, H & Ohyama, A.: "Development of triaxial test apparatus capable of measuring elastic wave velocities for the evaluation of liquefaction resistance of partly saturated sand"36th Annual Conference of Japan

蒲田，K.，石原，K.

鎌田邦夫, 石原研而, 塚本良道, 中澤博志, 大山敦郎: "不飽和砂の液状化抵抗の評価を目的とした弾性波速度計測の可能な三軸試験機の開発"第36回地盤工学研究発表会講演概要集. 439-440 (2001)

Kunio Kamata、Kenji Ishihara、Yoshimichi Tsukamoto、Hiroshi Nakazawa、Atsushi Oyama：“开发能够测量弹性波速度的三轴试验机，用于评估非饱和砂的抗液化性”第36届岩土工程研究会议演讲摘要集。 439-440 (2001)

中澤博志, 石原研而, 塚本良道, 大山敦郎, 鎌田邦夫: "砂のP波速度及び液状化特性に及ぼす飽和度の影響"第26回地震工学研究発表会論文集. 625-628 (2001)

Hiroshi Nakazawa、Kenji Ishihara、Yoshimichi Tsukamoto、Atsuro Oyama、Kunio Kamata：“饱和度对纵波速度和砂土液化特性的影响”第26届地震工程研究会议论文集625-628（2001）。

Nakazawa, H., Ishihara, K., Tsukamoto, Y., Ohyama, A. & Kamata,K.: "Influence of degree of saturation on P-wave velocity and liquefaction resistance"26th Japan Conference of Earthquake Engineering. 625-628 (2001)

中泽 H.、石原 K.、冢本 Y.、大山 A.

鎌田, 石原, 塚本, 中澤, 大山: "不飽和砂の液状化抵抗の評価を目的とした弾性波速度計測の可能な三軸試験機の開発"第36回地盤工学研究会発表会講演集. Vol.1. 435-436 (2001)

Kamata、Ishihara、Tsukamoto、Nakazawa、Oyama：“开发能够测量弹性波速度的三轴试验机，用于评估非饱和砂的液化阻力”第 36 届岩土工程研究会议论文集第 435 卷-。 436（2001）