Progressive failure mechanism of reinforced ground and its application to limit state design

加筋地基渐进破坏机制及其在极限状态设计中的应用

• 批准号: 09650555
• 负责人: OTANI Jun
• 金额: $ 1.98万
• 依托单位: Kumamoto University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650555/
• 关键词: ground failure; Earth reinforcement; Local deformation; Model test; Image analysis; Visualization; Bearing capacity; ground model by aluminium rods; アルミ某積層体

Design methods for earth reinforcement structures are mainly based on the limit equilibrium method which assumes the location and the shape of failure mechanism. In addition, in the current design method, it is assumed that the failure mechanism of the reinforced foundation ground is the same as that of non-reinforced foundation ground and the effect of reinforcing material is added in the design calculation in term of its tensile strength. Considering the future trend of the design method, it should be optimized from an economical point of view. This has been achieved by the development of "limit state design". Also, the new feasibility or application of this design should be the next target. For this purpose, it is necessary to investigate actual behavior of the reinforced foundation ground on both deformation and failure mechanism. According to the effect of earth reinforcement, it may be considered that the reinforcing effect is deeply related with the localization of deformation a … More nd progressive failure.The purpose of this research is to investigate the behavior of real progressive failure of the reinforced foundation ground and to establish a valid quantitative design calculation which could be based on the real failure mechanism. First of all, a series of model loading tests using the simulation of foundation ground by aluminum rods are conducted, in which the length and the property of the reinforcing material are varied. Based on the results of the loading tests, not only the bearing capacity but also the mechanism of progressive failure is investigated by using image processing analysis. Thus the progressive failure of the reinforced foundation ground are discussed in detail based on the microscopic observation and the analyzed results. These experimental results are concurrently analyzed by using "rigid-plastic finite element method". In the analysis, the model of reinforced soil is newly developed and also geometrical nonlinearity is taken into consideration in order to obtain the progressive behavior of the ground. The validity of the proposed method are verified by comparing with the results of the model tests. In addition, a simplified upper-bound mechanism appropriate to the observed mechanism is proposed, and applied to the test cases.The results achieved through this research are fundamental on the localization of deformation and progressive failure of the reinforced foundation ground. These results could be proved to be indispensable information for the future design method. Furthermore, the proposed analytical method for the reinforced foundation ground could have a great promise for the bearing capacity of reinforced earth structures. Less

加筋土结构的设计方法主要是基于极限平衡法，该方法假定了破坏机制的位置和形状。另外，现行的设计方法中，假定加筋地基与未加筋地基的破坏机理相同，并按其抗拉强度计算，在设计计算中加入了加筋材料的作用。考虑到设计方法的未来趋势，应从经济的角度进行优化。这是通过发展“极限状态设计”实现的。此外，这种设计的新的可行性或应用应该是下一个目标。为此，有必要研究加筋地基的变形和破坏机理。从加筋土的效果来看，加筋土的效果与变形局部化程度有很大关系， ...更多信息 本研究的目的是探讨加筋地基的真实的渐进破坏行为，并建立一个有效的定量设计计算，可以根据真实的破坏机制。首先，进行了一系列的模型加载试验，采用铝合金杆模拟地基，在不同的长度和增强材料的属性。根据加载试验结果，利用图像分析技术研究了试件的承载力和渐进破坏机理。在此基础上，根据微观观测和分析结果，对加筋地基的渐进破坏进行了详细的探讨。并对试验结果进行了刚塑性有限元分析。在分析中，加筋土的模型是新的发展，也考虑了几何非线性，以获得的进展性的基础。通过与模型试验结果的对比，验证了该方法的有效性。此外，本文还提出了一种与观测机理相适应的简化上限机理，并将其应用于算例分析，所得结果对研究加筋地基的变形局部化和渐进破坏具有一定的指导意义。这些结果可以被证明是不可缺少的信息，为未来的设计方法。此外，所提出的分析方法，加筋地基的地基可以有很大的承诺，加筋土结构的承载力。少

项目成果

J. Otani: "Bearing Capacity Analysis of Reinforced Foundations on Cohesive Soil" Int. Jour. of Geotextiles & Geomembranes. 16. 195-206 (1998)

J. Otani：“粘性土上加筋地基的承载力分析” Int。

山本健太郎: "熊本大学大学院自然科学研究科博士(工学)学位論文" Failure Mechanism of Reignforced Foundation Ground and Its Bearing Capasity Analysis, 147 (1998)

山本健太郎：《熊本大学自然科学技术研究生院博士（工学）论文》加固地基的破坏机理及其承载力分析，147（1998）

H.Kusuda: "Progressive Failure Mechanism and Bearing Capacity of Reinforced Ground" Master Thesis Kumamoto University. (1998)

H.Kusuda：“渐进破坏机制和加固地基的承载能力”硕士论文熊本大学。

K.Yamamoto: "Bearing capacity analysis of reinforced foundation ground" Proc.of 7th Int.Conf.of the Association for Compurter Methods and Advances in Geomechanics. 2339-2344 (1997)

K.Yamamoto：“加固地基承载力分析”计算机方法与地质力学进展协会第七届国际会议论文集。

J.Otani: "Bearing Capasity Analysis of Reinforced Foundations on Cohesive Soil" International Journal of Geotextiles & Geomembranes. 16. 195-206 (1998)

J.Otani：“粘性土上加筋基础的承载能力分析”国际土工织物杂志