Study on the evaluation method of in-situ deformation-strength characteristics of sand ground

砂地基原位变形强度特性评价方法研究

• 批准号: 61460162
• 负责人: TOKI Shosuke
• 金额: $ 2.5万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1986
• 资助国家: 日本
• 起止时间: 1986 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-61460162/
• 关键词: Anisotropy; Constitutive Equation of Soil; Dilatancy; Hysteresis; Sand; Shear Strength; Soil Structure; 履歴; 液状化; 砂質土; 応力-ひずみ関係; 静止土圧

The following results were obtained from the experimental and analytical research aimed to study the rational procedures to evaluated the stress-deformation behavior of sand ground.1. After a series of experiment, using hollow cylinder torsional shear test apparatus, assuming that a sand possess inherent and induced anisotropic mechanical properties, the following facts were pointed out. 1) Although shear strength was not affected by the induced anisotropy in this study, it is affected by the inherent anisotropy. The angle of shear resistance showed its minimum value when the direction of major principal stress deviates 75'from the direction parpendicular to the bedding plane of the test specimen. 2) In both shear and volumetric deformation behavior, considerable effects of inherent anisotropy was observed. As to the induced anisotropy, the decline of rigidity against shear deformation was largest when the deviation of current principal stress direction from the previous one is 75゜ . 3) Strain path was observed to deviate to the direction of bedding plane due to the inherent anisotropy, and to deviate to the direction away from the previous loading direction.2. A constitutive model for sand having anisotropic mechanical properties based on the concept of multi-directional sliding surfaces was examined its validity. 1) The model, which bases on the postulation that the resistance against shear deformation is the lowest on the bedding plane and appropriate shear deformation behavior is able to be characterized for every potential sliding surface, was proved valid to evaluate the anisotropic deformation behavior of sand. 2) Adopting Masing's rule to model the Bauschinger's effect on the shear deformation behavior on potential sliding surface, characteristics of strain path direction, effect of induced anisotropy on shear behavior and so forth were proved to be evaluated practically well by the constitutive model.

通过试验研究和分析研究，得出了评价砂土地基应力-变形性状的合理方法。通过一系列试验，利用空心圆柱体扭转剪切试验装置，假定砂土具有固有的和诱发的各向异性力学性质，指出了以下事实。1)抗剪强度虽然不受诱导各向异性的影响，但受固有各向异性的影响。当主应力方向偏离试件垂直于试件层面方向的75‘时，剪切阻力角出现最小值。2)在剪切和体积变形行为中，观察到固有各向异性的显著影响。对于诱导各向异性，当当前主应力方向与以前的主应力方向偏差为75゜时，刚度对剪切变形的影响最大。3)由于固有的各向异性，应变路径偏离了层理方向，并偏离了先前加载方向。检验了基于多向滑动面概念的砂土各向异性本构模型的有效性。1)该模型假定砂土在层理面上的剪切变形阻力最小，能够描述每个潜在滑动面的剪切变形特性，是评价砂土各向异性变形特性的有效模型。2)采用马辛格准则模拟包辛格效应对潜在滑动面剪切变形行为的影响，应变路径方向特征、诱发各向异性对剪切行为的影响等都被本构模型较好地评价。

项目成果

土岐祥介: 土質工学会北海道支部技術報告集. 28. 133-140 (1988)

Shosuke Toki：日本土壤工程学会北海道分会技术报告集 28. 133-140 (1988)。

三浦清一: 土質工学研究発表会発表講演集. 23. (1988)

Seiichi Miura：土壤工程研究会议论文集。23。（1988）

三浦均也: 土質工学会北海道支部技術報告集. 28. 115-124 (1988)

Hitoshi Miura：日本土壤工程学会北海道分会技术报告。28. 115-124 (1988)

三浦清一: 土質工学研究発表会発表講演小. 23. (1988)

Seiichi Miura：在土壤工程研究会议上的小演讲。23.（1988）

toki, Shosuke.: "Sand behavior under principal stress axes rotation" Proc. 8ARC., ICSMFE. 1. 113-116 (1987)

toki, Shosuke.：“主应力轴旋转下的沙子行为”Proc。