Resarch on transition of dynamic failure of soils.

土体动力破坏转变研究。

基本信息

批准号：
10450178
负责人：
MATSUI Tamotsu
金额：
$ 7.36万
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：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10450178/
关键词：
dynamic failure mechanism Liguifaction Cyclic shear failure intermediate soils Plasticity Index fine content Clay minerals Physical characteristics of soils 繰返し(ねじり)三軸試験

项目摘要

Generally, in designing the civil engineering structures, engineers use the angle of internal friction f for sands or cohesion c for clays. Most of soils, however, have a various particle size distribution between sands and clays, which are called intermediate soils. They are dealt as clays taking into consideration safety of the structure. On the other hand, since the liquefaction took place for decomposed granite during Hyogoken-Nambu Earthquake in 1995, some researchers have investigated the cyclic behavior of the intermediate soils. However, their mechanical properties have not elucidated yet.In this research project, a series of both static and cyclic triaxial tests in addition to cyclic torsional tests of the intermediate soils to investigate the relationship between static and cyclic behavior of the intermediate soils and soil properties. As the results, the static and cyclic strength decreases as clay content increases. Also, mineral composition of clay has an influence of the static and cyclic strength of the intermediate soils.Also, the bender element tests during cyclic torsional tests were carried out in order to investigate the relationship between shear modulus degradation and soil properties of the intermediate soils. It was found that the shear modulus degrades sharply in the first 20 cycles during cyclic torsional test due to the increase of pore water pressure. The shear modulus degration decreases as the clay content increases.

通常，在设计土木工程结构时，工程师将内部摩擦F的角度用于沙子或粘土的凝聚C。但是，大多数土壤在沙子和粘土之间具有各种粒径分布，这些分布称为中间土壤。它们被视为粘土考虑到结构的安全性。另一方面，由于液化发生在1995年在北南北部地震期间发生分解的花岗岩，因此一些研究人员研究了中间土壤的循环行为。然而，它们的机械性能尚未阐明。在该研究项目中，除了对中间土壤的环状扭转测试外，一系列静态和环状三轴测试，以研究中间土壤和土壤特性的静态和环状行为之间的关系。由于结果，随着粘土含量的增加，静态和循环强度会降低。同样，粘土的矿物组成具有中间土壤的静态和循环强度的影响。此外，还进行了循环扭转测试期间的弯曲元素测试，以研究剪切模量降解与中间土壤的土壤性质之间的关系。发现由于孔隙水压的增加，剪切模量在循环扭转测试中的前20个周期中急剧降解。随着粘土含量的增加，剪切模量降低减小。