Behaviors of soil structure in shearing zone by the ring shear test and its characteristics

剪切带土结构的环剪试验行为及其特征

• 批准号: 09650544
• 负责人: UNO Takao
• 金额: $ 2.11万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650544/
• 关键词: Ring shear; Direct shear; sand and gravel; Friction against mineral board; soil structure; Distribution of void diameter; 残留強度; 土のせん断強さ; 異種材料

In this research, two kinds of results are obtained as follows, although comparisons between strain-controlled and stress-controlled ring shear test characteristics are omitted in final report, because the latter test adjustment have made much time.(A) Characteristics of ring shear test for sandy soils(1) The magnitude of ring shear strain is necessary to 0.5-1.0 for sandy soils and 0.5 for coarse sand.(2) Adjustment of shearing strength by volume strain as dilatancy for sandy soil at the ring shear test isn't so great in comparison with the adjustment for silty soils.(3) Composition of fine and coarse sand particles makes effect on shearing resistance. The more the coarse particles fraction is, the greater the strength of sandy soil specimen is.(4) Friction between coarse sand and mineral board is not so great against the expectation of empirical engineers.(5) The strength of sandy soils by direct shear test result is thought to be too great for design purpose compared with ring shear test, and the ring shear test is better even for sands.(B) Estimation of soil structure in shear zone by pore diameter distribution(6) Using the soil moisture retention curve, we can get the distribution of void diameter, which is called as the "moisture method".(7)The most frequent void diameter of sands after shear turns to be slightly greater than before shear, for example, as a diameter in 0.075 mm turns to 0.085 mm for fine sands.

在这项研究中，虽然最终报告中省略了应变控制和应力控制环剪试验特性的比较，但得到了以下两种结果：砂土环剪试验的特点(1)砂土环剪应变的大小为0.5-1.0，粗砂为0.5-1.0；(2)砂土在环剪试验中因剪胀引起的体积应变对抗剪强度的调整不如粉质土大。(3)粗、细砂颗粒组成对抗剪强度的影响。粗颗粒含量越多，砂土试件的强度越大。(4)粗砂与矿物板之间的摩擦力没有经验工程师预期的那么大。(5)与环剪试验相比，砂土的直剪试验结果被认为强度太大，环剪试验甚至更适合于砂土。(2)通过孔隙直径分布来估计剪切带内的土体结构。(6)利用土壤持水曲线，可以得到孔隙直径的分布，(7)砂土剪切后最常见的孔隙直径变得比剪切前略大，例如细砂的直径从0.075 mm变为0.085 mm。

项目成果

Satoru Nakamura: "Effect of Lubricants and Manicure Method on Reduction of Propulsion Force" Proc. 15th Int. NO-DIG'97, Taipei(Taiwan). 2-1-1-15 (1997)

中村悟：“润滑剂和美甲方法对推进力降低的影响”Proc。

Takao UNO: "Estimation of Void Diameter Distribution of Sands" Proceedings of the 11th Asian Regional Conference on ISSMGE. (発表予定). (1999)

Takao UNO：“沙子空隙直径分布的估计”第 11 届 ISSMGE 亚洲区域会议论文集（待提交）。

M.Fukuda and S.Suwa and T.Uno: "Major effect of grain size distribution to coefficient Of permeability of marine clay" Proc.Of 7^<th> Offshore and Polar Eng.Vol.1. 634-638 (1997)

M.Fukuda、S.Suwa 和 T.Uno：“粒度分布对海洋粘土渗透系数的主要影响”Proc.Of 7^<th> Offshore and Polar Eng.Vol.1。

Toshio Sugii: "Critical Velocity of Multiple Particles for Seepage Failure" IS-NASOYA'97 : Deformation and Progressive Failure in Geomechanics. 611-616 (1997)

Toshio Sugii：“渗流破坏的多个粒子的临界速度”IS-NASOYA97：地质力学中的变形和渐进破坏。

M.Fukuda and T.Uno: "Role of mean size index and grain size distribution in permeability phenomenon (in Japanese)" J.of Geotechnical Engineering (JSCE.). No.561/III-38. 193-204 (1997)

M.Fukuda 和 T.Uno：“平均尺寸指数和粒度分布在渗透现象中的作用（日语）”J.of Geotechnical Engineering (JSCE.)。