Deformation characteristics of clays at deep position of ground and its time dependency

地基深层黏土变形特征及其时间依赖性

基本信息

批准号：
03650405
负责人：
MATSUI Tamotsu
金额：
$ 1.02万
依托单位：
Osaka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

In this study, the effect of time dependency on the mechanical characteristics of undisturbed clays is investigated, which is in the Pleistocene deposits at the off-Senshu area in Osaka Bay. Also, the method for predicting deformation of the ground is proposed. The main conclusions are summarized as follows:1. A constant rate of strain consolidation apparatus for semi-high pressure was developed. The consolidation characteristics of undisturbed clays taken from the Pleistocene deposits at the off-Senshu area in Osaka Bay was investigated. Firstly, the effect of such test conditions as strain rate and back pressure on the consolidation characteristics was investigated. It is found that the strain rate significantly affects consolidation yield stresses in the constant rate of strain consolidation tests. Next, a constant rate of strain consolidation apparatus for semi-high pressure could be applicable to the undisturbed clays in the Pleistocene deposits, which have higher yield stresses than the alluvial clays.2. The undrained shear characteristics of the undisturbed clays in the Pleistocene deposits was investigated through mini-triaxial tests. The undrained shear tests of the reconstituted clays were carried out to investigate the "aging" effect on shear characteristics. The linear relationship between logarithmic maximum deviator stresses and void ratios was observed on both the undisturbed and reconstituted clays. It was shown that the effect of initial void ratio on shear strengths can be excluded through using the void index or the e_L.3. A method for determining elasto-viscoplastic parameters for the undisturbed clays in the Pleistocene deposits using mini-triaxial tests and consolidation tests was proposed. The reliability of the determined parameters was investigated through the numerical simulation analysis of deformation behavior in triaxial tests and construction of a man-made island.

在这项研究中，研究了时间依赖对未受干扰的粘土机械特征的影响，该粘土在大阪湾外苏外地区的更新世沉积中进行了研究。同样，提出了预测地面变形的方法。总结总结如下：1。开发了半高压的应变巩固设备的恒定速率。研究了从大阪湾的苏期区域的更新世沉积物中取出的不受干扰的粘土的合并特性。首先，研究了诸如应变速率和背压对巩固特性等测试条件的影响。发现应变速率显着影响应变巩固测试恒定速率的固结屈服应力。接下来，半高压的应变巩固设备的恒定速率可适用于更新世沉积物中未受干扰的粘土，其屈服应力高于冲积粘土。2。通过迷你三轴测试研究了更新世沉积物中未受干扰的粘土的未排水剪切特性。进行了重构粘土的未排水剪切试验，以研究对剪切特性的“衰老”影响。在不受干扰的和重构的粘土上都观察到对数最大偏移应力与空隙比之间的线性关系。结果表明，可以通过使用void索引或e_l.3来排除初始空隙比对剪切强度的影响。提出了一种确定更新世沉积中未受干扰粘土的弹性胶状参数的方法，并提出了小三轴测试和整合测试。通过对三轴测试中的变形行为和人造岛的构建的变形行为的数值分析来研究确定的参数的可靠性。