Study on the evaluation of the mechanical properties of sandy grounds and their test methods

沙地基力学性能评价及其试验方法研究

• 批准号: 60850095
• 负责人: TOKI Shosuke
• 金额: $ 4.99万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60850095/
• 关键词: liquefaction; cohesionless soil; stress-strain relationship; bearing capacity of soils; 地震; 砂質士; 支持力

The following conclusions can be drawn based on the co-operative research on the mechanical behavior of cohesionless soils;1. Deformation behavion at any stress system and fabric anisotropy and constitutive equation of sandy grounds. (1) By evaluating the fabric anisotropy and the relative magnitude of the intermediate principal stress appropriately, the deformation-strength characteristics of sand obtained by the trosional simple shear tests agreed well with that of the plane strain compression tests having the fixed principal stress axes. (2) An yield function, the extended Drucker-Prager's yield function, is formulated using explicitly the fabric tensor which is an index measure for representing the anisotropy of three-dimensional particle orientation. (3) A constitutive model for granular materials by which the general strain increments are directly related to the general stress increments is derived. The model proposed predicts the strains not only due to consolidation and shear, but also due to principal stress rotation.2. Evaluation of in-situ liquefaction strength of sand grounds. An evaluation method of liquefaction strength of sandy grounds was proposed based on an empirical correlation between the field performance observed during previons earthquakes and geological records.3. Undrained cyclic triaxial test methods. A co-operative test program of cyclic undrained triaxial tests was performed following the newly specified test procedures by 48 laboratories in Japan for Toyoura sand specimens. The scattering of the data was found mainly due to different specimen shape, different consolidation method and asymmetry in the cyclic stress amplitude.

通过对无粘性土力学特性的合作研究，可以得出以下结论：1。桑迪地基在任意应力体系下的变形行为及组构各向异性与本构方程。(1)通过对组构各向异性和中间主应力相对大小的适当评价，扭剪试验得到的砂土变形强度特性与主应力轴固定的平面应变压缩试验结果吻合较好。(2)一个屈服函数，扩展Drucker-Prager的屈服函数，制定明确使用的织物张量，这是一个指标衡量代表三维颗粒取向的各向异性。(3)本文导出了一个广义应变增量与广义应力增量直接相关的粒状材料本构模型。该模型不仅可以预测固结和剪切变形，还可以预测主应力旋转变形.砂土地基原位液化强度评价。根据以往地震现场观测资料与地质资料的经验相关性，提出了一种桑迪液化强度的评价方法.不排水循环三轴试验方法。根据日本48家实验室新规定的试验程序，对丰浦砂试件进行了循环不排水三轴试验的合作试验程序。试验结果的分散性主要是由于试件形状、固结方法和循环应力幅的不对称性造成的。

项目成果

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。

Soils and Foundations,JSSMFE. 26-1. (1986)

土壤和地基，JSSMFE。

土質工学会 土質工学研究発表会講演集. 21. (1986)

日本土壤工程学会，土壤工程学研究报告集，21。（1986）

陶野郁雄: 日本建築学会論文報告書.

末野郁夫：日本建筑学会论文报告。

土岐祥介: Proc.8ARC.,ICSMFE. 1. 113-116 (1987)

Shosuke Toki：Proc.8ARC.，ICSMFE。1. 113-116 (1987)