Research on Elucidation of Failure Mechanism in Reinforced Earth Structures and Introduction of the Reliability Design Method

加筋土结构失效机理阐明及可靠性设计方法介绍研究

基本信息

批准号：
11555129
负责人：
MATSUI Tamotsu
金额：
$ 8.58万
依托单位：
OSAKA UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Steel grid reinforced earth, which has both frictional and bearing reinforcing mechanisms, is one of grid type reinforced earths. It is more useful than conventional reinforced earth methods. Because available design methods aren't effective for the steel grid reinforced earth, we tried to establish the effective design method using the reliability design theory.We investigated the bearing mechanism of steel grid reinforced earth by a laboratory pullout test in the first year. Then, we proposed an equation to estimate bearing resistance of steel grid reinforced earth based on the laboratory pullout test result, and the equation was examined through a comparison with a field pullout test result. The estimated pullout resistance agreed with the laboratory test result, however, it was smaller than that measured in the field. Also, to investigate failure mechanism of reinforced earth, we made a centrifugal model test apparatus.In the second year, we performed a series of laboratory pullout test and field measurement. To introduce a reliability design method to reinforced earth structures, it was necessary to deeply investigate its mechanical behavior. Especially, the dynamic behavior of steel grid reinforced earth was the most important in the countries which have many earthquakes like Japan. Therefore, we performed a series of cyclic pullout test under the cyclic overburden stress. The maximum pullout resistance under the cyclic stress condition was much less than that under the static stress condition. The relationship between deformation of steel grid reinforced earth wall and rainfall was also investigated by a field measurement. It was found that deformation of the reinforced earth wall was related to both total amount and period of the rainfall.

具有摩擦和轴承加强机制的钢网格增强地球是网格类型的增强地球之一。它比常规的增强地球方法更有用。由于可用的设计方法对于钢网格增强的地球不有效，因此我们尝试使用可靠性设计理论建立有效的设计方法。我们通过第一年的实验室拉力测试研究了钢网格增强地球的轴承机理。然后，我们提出了一个方程式，以根据实验室拔出测试结果估算钢网格增强地球的抗轴承性，并通过与现场拔出测试结果进行比较来检查方程。估计的拔出电阻与实验室测试结果一致，但是，它小于田间测量的结果。此外，为了研究增强地球的故障机制，我们制作了一个离心模型测试设备。第二年，我们进行了一系列实验室拉拔测试和现场测量。为了引入一种可靠性设计方法来增强地球结构，有必要深入研究其机械行为。尤其是，在像日本这样许多地震的国家中，钢网格增强地球的动态行为是最重要的。因此，我们在循环过度应力下进行了一系列循环拉扯测试。在循环应力条件下的最大拉力电阻远小于静态应力条件下的电阻。还通过野外测量研究了钢网格增强的地球壁的变形与降雨之间的关系。发现增强的土壁的变形与降雨的总量和周期有关。