A Study on Change in Microstructures and Mechanical Properties of Clayey Soils Subjected to High Temperature Histories

高温历史作用下粘土微观结构和力学性能变化研究

基本信息

批准号：
11650508
负责人：
MORIWAKI Takeo
金额：
$ 2.37万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
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

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650508/
关键词：
High Temperature Triaxial Test Microstructures Consolidation Properties Shear Properties High Temperature History Temperature Effect Clavev Soil

项目摘要

A triaxial test apparatus which can conduct consolidation, shear and permeability tests under high temperature conditions from 50℃ to 2OO℃ was developed in this study. In order to clarify consolidation and shear characteristics of clayey soils a series of consolidated-undrained triaxial compression tests was carried out using the developed triaxial test apparatus for kaolin clay and bentonite clay under several temperature conditions. As the results, it was found that mechanical properties of clay under 1OO℃ are on the extended lines forecasted from temperature effects below 1OO℃ and no significant change in mechanical properties of clay appears under about 1OO℃. It was also found that the compression strength increases for both kaolin and bentonite clays with the increase of test temperature, and the gradient of the critical state line decreases for kaolin clay but increases for bentonite clay with the increase of test temperature. Moreover, it was found that although the compression strength increases for both clays with the increase of test temperature, the increment of the compression strength corresponding to the decrease of the void ratio due to the increase of test temperature does not appear for both clays.A computer image processing method was developed in order to evaluate quantitative microstructures of clays. Density distributions of Scanning Electron Microscope photographs were measured and their power spectrum were analyzed in this method. It was found from the results obtained by this evaluation method that high temperature reconsolidated clays have a random structure and room temperature reconsolidated clays have an oriented structure.

在这项研究中，开发了一种在高温条件下从50°至2OO中进行合并，剪切和渗透率测试的三轴测试设备。为了澄清粘土质土壤的固结和剪切特性，使用开发的三轴粘土和膨润土粘土在几种温度条件下，使用开发的三轴测试设备进行了一系列固结液三轴压缩测试。结果是，发现粘土在1OO下的机械性能是在1OO低于1OO的温度效应的扩展线上，并且在约1OO℃下，粘土机械性能的机械性能没有显着变化。还发现，随着测试温度的升高，高岭土和膨润土粘土的压缩强度都会提高，而高岭土的临界状态线的梯度下降，但随着测试温度的升高，膨润土粘土的增加。此外，发现，尽管两种粘土的压缩强度随测试温度的升高都会增加，但与两种粘土的测试温度的升高相对应降低，压缩强度的增加对应于void比的降低。测量了扫描电子显微镜照片的密度分布，并在此方法中分析了它们的功率谱。从通过这种评估方法获得的结果发现，高温重塑的粘土具有随机结构，室温重新溶解的粘土具有方向的结构。