THE STRENGTH AND DEFORMATION CHARACTERISTICS OF CLAY SUBJECTED TO CYCLIC SHEAR STRESS

循环剪应力作用下粘土的强度和变形特性

• 批准号: 04650444
• 负责人: TONOSAKI Akira
• 金额: $ 1.22万
• 依托单位: KANAZAWA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1992
• 资助国家: 日本
• 起止时间: 1992 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-04650444/
• 关键词: Cyclic loading; Overconsolidation; Triaxial test; Dynamic; Shear strength; 三軸圧縮試験; 圧密; 間隙水圧; 火山灰質粘性土; ダイレイタンシー; 粘土

In this paper, strength and deformation characteristics of clay (Kanto loam) which has undegone cyclic shear is investigated by cyclic triaxial tests. In the tests, the effect of the overconsolidation ratio on static and dynamic strength was examined under Ko overconsolidation condition created by loading pre-load and Ko normal consolidation. The residual pore water pressure, volumetric change and undrained shear characteristics were examined using the specimens which did not break under cyclic shear. The results which were obtained from this study are summarized as follows.1.As for Kanto loam under isotropic consolidation, Ko normal consolidation or Ko overconsolidation, the line of undrained cyclic shear breaking overlaps the line of static undrained shear breaking.2.Unlike its effect on static strength, pre-loading does not induce a significant increase of dynamic strength and ultimate yield strength defined by axial strain and the number of repeitions of applied deviator stress. In … More other words, dynamic strength can not be expected to increase as much as static strength with the same pre-loading. The ultimate yield strength and its corresponding static strength decrease as the overconsolidation ratio increases. Therefore, we cannot expect the dynamic strength to increase as much as the static strength increases with pre-loading.3.The relationship between effective stress increase and volumetric change obtained by residual water pressure can be expressed by a particular type of straight line, irrespective of overconsolidation ratios. A similar relationship in regard to clay has been reported by Matsui and Yasuhara.4.The increase of strength due to re-consolidation after cyclic loading is proportional to the increase of effective pressure due re-consolidation in the specimens under Ko normal consolidation. However, the strength of the specimens under Ko overconsolidation does not increase even though the specimens are also re-consolidated. The soil structure change due to cyclic loading nulified the increase of strength due to re-consolidation.5.The lager the cyclic loading stress is, the more the deformation modulus E50 of re-consolidated specimens decreases, even though the strength increases by re-consolidation after cyclic loading. The larger the OCR is and the more the specimens are affected by a reversal of principal stress, the more the decrease of strength and deformation modulus is significant. Less

本文通过循环三轴试验，研究了循环剪切作用下粘土（关东亚粘土）的强度和变形特性。试验中，在加载预压和Ko法向固结共同作用下，研究了Ko超固结条件下超固结比对静、动强度的影响。利用在循环剪切作用下不破裂的试件，研究了残余孔隙水压力、体积变化和不排水剪切特性。研究结果表明：1.对于关东亚粘土，在各向同性固结、Ko正常固结和Ko超固结条件下，不排水循环剪切破坏线与静力不排水剪切破坏线重合; 2.与静力强度的影响不同，表示“前加载不会引起动强度和由轴向应变和施加的重复次数定义的极限屈服强度的显著增加。偏应力在 ...更多信息 换句话说，在相同的预载荷下，不能期望动态强度增加与静态强度一样多。随着超固结比的增大，土体的极限屈服强度和相应的静强度均减小。因此，我们不能期望动强度的增加与静强度的增加一样多。3.有效应力增加与残余水压力引起的体积变化之间的关系可以用一条特殊类型的直线来表示，而与超固结比无关。对于粘土，Matsui和Yasuhara也报道了类似的关系。4.在Ko法向固结条件下，循环荷载后再固结引起的强度增加与再固结引起的有效压力增加成正比。然而，Ko超固结下的试件的强度并没有增加，即使试件也被重新固结。循环荷载作用下土体结构性的变化使再固结强度的提高变得无效。5.循环荷载应力越大，再固结试件的变形模量E50降低越多，即使循环荷载作用后再固结强度有所提高。OCR越大，受主应力反转影响越大，强度和变形模量的降低越显著。少

项目成果

外崎,明・廖,紅建・赤石,勝・稲田,倍穂: "プレロードを受けた関東ロームの繰返しせん断特性" 第29回土質工学研究発表会講演集. 発表予定. (1994)

Tonosaki、Akira、Liao、Hongjian、Akaishi、Katsu 和 Inada、Baiho：“预加载关东壤土的重复剪切特性”第 29 届土壤工程研究会议论文集（1994 年）。

外崎,明・廖,紅建・赤石,勝: "繰返し載荷履歴を受けた関東ロームの変形特性" 第21回関東支部技術研究発表会講演概要集. 312-313 (1994)

Tonosaki、Akira、Liao、Hongjian、Akashi、Masaru：“反复加载历史下关东壤土的变形特征”第21届关东分会技术研究会议演讲摘要312-313（1994）。

外崎明,廖紅建,赤石勝: "繰返し載荷履歴を受けた関東ロームの変形特性" 第21回関東支部技術研究発表会講演概要集. 312-314 (1994)

Akira Tonosaki，Hongjian Liao，Masaru Akaishi：“反复加载历史下关东壤土的变形特征”第21届关东分会技术研究报告摘要312-314（1994）。

外崎明・廖紅建・明石勝: "繰返し載荷履歴を受けた関東ロームの変形特性" 第21回関東支部技術研究発表会講演概要集. 312-314 (1994)

Akira Tonosaki、Hongjian Liao、Masaru Akashi：“重复加载历史下关东壤土的变形特征”第 21 届关东分会技术研究报告摘要 312-314（1994 年）。

外崎明・廖紅建・明石勝・稲田倍穂: "プレロードを受けた関東ロームの繰返しせん断特性" 第29回土質工学研究発表会講演集. 903-904 (1994)

Akira Tonosaki、Hongjian Liao、Masaru Akashi 和 Beho Inada：“预载关东壤土的重复剪切特性”第 29 届土壤工程研究会议论文集 903-904（1994 年）。