An Investigation on Stability of Clay Ground Improved by Sand Compaction Piles

压实砂桩改良粘土地基稳定性研究

• 批准号: 63850112
• 负责人: NAKASE Akio
• 金额: $ 3.65万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Developmental Scientific Research
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-63850112/
• 关键词: S.C.P.; Clay; Gravity Quay Wall; Backfilling; Lateral Resistance; Lateral Displacement; Stability; Model Tests; サンドコンパクションパイル; 盛土

A series of centrifuge tests was conducted in an attempt to study the effect of the weight of a caisson and the width and the area ratio of improvement by sand Compaction piles(S.C.P.) on the stability of improved ground under a backfilled caisson. Following conclusions are derived from this study. l.Horizontal deformations are much more dominant than vertical deformations when a backfilled caisson is built on soft clay improved with S.C.P. 2. For improved ground, a well-defined circular slip surface is observed. However for improved ground, horizontal deformations increase gradually with the increase of horizontal load and at a certain load the horizontal deformations suddenly start to increase, showing no slip surface in the ground. This leads to a conclusion that consideration of horizontal deformations is more important than that of stability against failure for this type of structure. 3. When the safety factor calculated by the modified Fellenius' stability analysis exceeds 1.4, considerable horizontal deformation appear. This leads to a conclusion that the minimum safety factor for this type of problem should be taken as 1.5.

进行了一系列离心机试验，试图研究沉箱重量以及压实砂桩(S.C.P.)改良的宽度和面积比对回填沉箱下改良地基稳定性的影响。本研究得出以下结论。 l.当在用S.C.P.改良的软粘土上建造回填沉箱时，水平变形比垂直变形更占主导地位。 2. 为了改善地面，观察到明确的圆形滑面。但对于改良后的地基，随着水平荷载的增加，水平变形逐渐增大，到一定荷载时，水平变形突然开始增大，地面不再出现滑移面。由此得出的结论是，对于此类结构，考虑水平变形比考虑破坏稳定性更重要。 3、当修正费勒尼乌斯稳定性分析计算的安全系数超过1.4时，出现相当大的水平变形。由此得出的结论是，此类问题的最小安全系数应取为 1.5。

项目成果

飯島興二,広岡明彦,竹村次朗,中瀬明男: "盛工荷重を受けたSCP地盤の安定性について" 第24回土質工学研究発表会講演概要集. 2. 1895-1896 (1989)

Koji Iijima、Akihiko Hirooka、Jiro Takemura、Akio Nakase：“论路堤荷载作用下 SCP 地面的稳定性”第 24 届土壤工程研究会议讲座摘要 2。1895-1896 (1989)。

Ootsuka, J., Takemura, J.Okadome, K. and Nakase, A.: "The stability of caisson wall on soft clay improved by S.C.P.." Procs.24th Annual Conference of Japanese Society of Soil Mechanics and Foundation Engineering, Vol.1, pp. 1897-1898, 1989.

Ootsuka, J.、Takemura, J.Okadome, K. 和 Nakase, A.：“软粘土上沉箱墙的稳定性通过 S.C.P. 得到改善”，日本土壤力学与基础工程学会第 24 届年会，卷。

Watabe, Y., Suemasa, N., Takemura, J., Nakase, A. and Hirooka, A.: "Stability of soft clay improved with S.C.P. supporting backfilled gravity caisson." Procs.25th Annual Conference of Japanese Society of Soil Mechanics and Foundation Engineering, 1990.

Watabe, Y.、Suemasa, N.、Takemura, J.、Nakase, A. 和 Hirooka, A.：“通过 S.C.P. 支撑回填重力沉箱提高了软粘土的稳定性。”

大塚寿一,竹村次朗,岡留孝一,中瀬明男: "SCP地盤上の重力式護岸の安定性に関する研究" 第24回土質工学研究発表会講演概要集. 2. 1897-1898 (1989)

Juichi Otsuka，Jiro Takemura，Koichi Okadome，Akio Nakase：“SCP地面重力式护岸稳定性研究”第24届土壤工程研究会议摘要2。1897-1898（1989）。

飯島興二,広岡明彦,竹村次朗,中瀬明男: 第24回土質工学研究発表会講演概要集. (1989)

Koji Iijima、Akihiko Hirooka、Jiro Takemura、Akio Nakase：第 24 届土壤工程研究会议摘要集（1989 年）。