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

广泛分布于非洲赤道地区的泥灰岩是一种具有体积变化特性的热带膨胀土。在雨季，泥灰岩的体积因高湿度而增加，而在旱季，泥灰岩的体积则减少。由于下部建筑物的重量不具有抵抗膨胀压力的承载力，收缩和膨胀引起的变形引起不均匀沉降和膨胀。通过对达喀尔周边地区的实地调查，根据建筑物类型、建筑物破坏类型和地质条件，对影响因素进行了分析。此外，还从达喀尔主要受损地区收集了样本。为了了解泥灰岩的物理力学性质和微观结构，将样品运往日本，并在日本进行了实验室试验。从这些测试的结果，泥灰岩的主要特征进行了详细的研究。由于泥灰岩的力学性质随含水量的变化而变化， ...更多信息 在各种含水量下进行实验室试验。研究了高含水量条件下的强度衰减和膨胀特性以及排水条件下的强度恢复和膨胀特性，旨在建立达喀尔地区土袋提高地基刚度的施工方法。为了确认土袋作为地基改良方法（Solpack法）的有效性，进行了使用土袋的各种试验。在实验结果的基础上，研究了Solpack方法的适用性，并进行了数值模拟。通过一系列的研究，提出并制定了Solpack法的设计标准和手册，为了在达喀尔地区推广Solpack法，在达喀尔市召开了由达喀尔地区的行政工程师、建筑工程师、研究人员和达喀尔大学Fall教授参加的技术会议。Solpack方法是为达喀尔地区的研究人员和工程师提供的一种适用于各种局部区域的方法。希望今后能由当地的研究人员开发出适合当地的详细设计手册。少

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。