A research of failure mechanism of tropical expansion soil in Africa and its countermeasure of symbiosis with nature

非洲热带膨胀土破坏机理及其与自然共生的对策研究

• 批准号: 15404013
• 负责人: YASHIMA Atsushi
• 金额: $ 8.19万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15404013/
• 关键词: Marl; differential settlement and swelling; Soil bag; design manual; 泥灰土(marl); 泥炭土; サンプリング

A kind of tropical expansion soil : Marl that widely spread in equatorial area of Africa has a feature of volumetric change in geotechnical field. The volume of Marl increase due to high moisture in rainy season, on the other hand the volume is reduced in dry season. As the weights of lower building do not have bearing resistance against swelling pressure, the deformation caused by shrinkage and expansion invoke differential settling and swelling. From the field investigations around Dakar, factors are investigated based on the type of building, type of damage for building and geological condition. In addition, samples are collected from the major-damaged area in Dakar. In order to understand the physical and mechanical properties and microstructure of Marl, the samples were shipped to Japan and laboratory tests were carried out in Japan. From the results of those tests, the main features of Marl is investigated in detail. As the mechanical feature of Marl changed with water content, l … More aboratory tests were conducted under various water contents. The reduction of strength and the swelling character in high water content condition andtherecovery of strength and swelling character under drainage condition are studied in the research.The practical goal of this research is to establish the construction method to improve the ground stiffness using soil bag in Dakar area. In order to confirm the effectiveness of soil bag as the ground improving method (Solpack-method), various tests using soil bag were conducted. Based on the experimental results, the applicability of Solpack-method is investigated and numerical simulations are carried out in addition. From a series of research, a standard and a manual for design of Solpack-method is proposed and established.In order to apply the Solpack-method in Dakar area, technical meetings are held in Dakar city with engineers of administration, builders, researchers in Dakar area and Professor Fall of Dakar University. Solpack-method, which is established to apply for various local regions in detail, is proposed for researchers and engineers in Dakar area. It is expected to develop the detail manual of design for local area by the researchers in those areas for the future. Less

一种热带膨胀土：广泛分布于非洲赤道地区的泥灰岩，在岩土工程领域具有体积变化的特点，雨季时泥灰岩体积增大，反之体积减小。旱季 由于下部建筑物的重量不具备抵抗膨胀压力的能力，收缩和膨胀引起的变形会引起不同的沉降和膨胀。根据达喀尔周围的现场调查，根据建筑物类型、损坏类型对影响因素进行了调查。用于建筑和此外，为了了解泥灰岩的物理力学性质和微观结构，还从达喀尔的重灾区采集了样品，并在日本进行了实验室测试。在这些试验中，详细研究了泥灰岩的主要特征，因为泥灰岩的力学特性随含水量的变化而变化，因此在不同含水量条件下进行了强度降低和高含水量条件下的膨胀特性。以及强度和肿胀特性的恢复本研究的实际目标是建立达喀尔地区使用土袋提高地面刚度的施工方法，以确认土袋作为地面改良方法（Solpack-）的有效性。方法），根据实验结果进行了各种测试，研究了 Solpack 方法的适用性，并通过一系列研究、Solpack 设计标准和手册进行了数值模拟。提出了方法并且为了在达喀尔地区应用Solpack方法，在达喀尔市召开了由达喀尔地区的管理工程师、建筑人员、研究人员和达喀尔大学法尔教授参加的技术会议，该技术会议是为应用各种技术而建立的。为达喀尔地区的研究人员和工程师提出了详细的局部地区设计手册，预计未来由这些地区的研究人员开发局部地区的详细设计手册。

项目成果

Sarr, A.M.: "Stress-dilatancy relation for highly structured soils"Proc.Of International Workshop on Prediction and Simulation Methods in Geomechanics. 61-64 (2003)

Sarr, A.M.：“高度结构化土壤的应力-剪胀关系”地质力学预测和模拟方法国际研讨会论文集。