Soft Soil Improvement by Vertical Sand piles

垂直砂桩改良软土

• 批准号: 02555110
• 负责人: MATSUO Minoru
• 金额: $ 2.94万
• 依托单位: Nagoya University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research (B)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02555110/
• 关键词: Bearing capacity; Consolidation; Elastic-Plastic; Sand pile; Vertical drain; Soil improvement; Permeability; 軟弱地盤; 変形

Sand Drains(1)The range of soil permeability which yields the variation of partial drain behavior was found10^<-7>cm/sec k 10^<-4>cm/secwhen a clay deposit of about 25 meters thick is considered.(2)When soil permeability lies on this particular range the bigger the load intensity, the more the partial drain effect should be expected.(3)The efficiency of sand drains is to be observed in a limited range of soil permeability and under a particular magnitude of load intensity.2. Sand Compaction Piles(1)The bearing capacity of soft clay with vertical sand compaction piles is extremely influenced by the stiffness of applied load. When load application through a rigidfooting is considered fully drained/swelling conditions for sand piles provide biggerbearing capacity than undrained/no swelling conditions. On the other hand, whenflexible load application such as embankment loading is the case, undrained conditionsgive bigger bearing capacity than fully drained/swelling condition.(2)The increase of the undrained strength of clay due to displacement and consolidation by sand pile installation should be correctly evaluated when relatively low sand replacement ratio is considered.

(1)当考虑约25米厚的粘土沉积时，导致部分排水行为变化的土壤渗透性范围为10^<-7>cm/秒，10^<-4>cm/秒。(2)土体渗透性在该特定范围内时，荷载强度越大，局部排水效应越大。(3)沙渠的效率是在有限的土壤渗透性范围内和在一定的荷载强度下观察到的。(1)竖向压砂桩对软土的承载力受外加荷载刚度的影响很大。当通过刚性基础的荷载施加被认为是完全排水/膨胀条件时，砂桩比不排水/无膨胀条件提供更大的承载能力。另一方面，当柔性荷载应用（如路堤荷载）时，不排水条件比完全排水/膨胀条件具有更大的承载能力。(2)在考虑较低的换砂率时，应正确评价砂桩安装对粘土位移固结带来的不排水强度的增加。

项目成果

A.Asaoka, M. Matsuo, T. Kodaka: "Undrained Bearing Capacity of clay with Sand Piles" Proc. of 9th Asian Regional Conferences on Soil Mechanics and Foundation Engineering.467-470 (1991)

A.Asaoka、M. Matsuo、T. Kodaka：“沙堆粘土的不排水承载力”Proc。

大塚 悟: "Characteristics of Deformation and Stability of Soilーstructure Systems on Soft Clay" 第26回土質工学研究発表会. (1991)

大冢悟：“软粘土上土结构系统的变形和稳定性特征”第26届土壤工程研究会议（1991）。

A.Asaoka,M.Matsuo,T.Kodaka: "Undrained Bearing Capacity of Clay with Sand Piles" Proceedings of the 9th Asian Regional Conferencs on Soil Mechanics and Foundation Engineering. 1. 467-470 (1991)

A.Asaoka，M.Matsuo，T.Kodaka：“砂桩粘土的不排水承载力”第九届亚洲地区土壤力学与基础工程会议论文集。

A.Asaoka, M. Nakano, M. Matsuo: "Prediction of the partially drained behavior of soft clays under embankment loading" Soils and Foundations. Vol. 32, No. 1. 41-58 (1992)

A.Asaoka、M. Nakano、M. Matsuo：“路堤荷载下软粘土部分排水行为的预测”土壤与地基。

浅岡 顕,小高 猛司,真下 佐知子: "複合地盤の支持力に及ぼす基礎の剛性の影響および打設時の排土の効果" 第4回地盤工学シンポジウム(土質工学会中部支部)発表論文集. 75-78 (1992)

Akira Asaoka，Takeshi Odaka，Sachiko Mashita：“地基刚度对复合地基承载力的影响以及浇筑过程中脱土的影响”第四届岩土工程学会论文集（日本土壤工程学会中部分会）75 -78。 1992）