文摘
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为进一步探讨饱和原状Q_2黄土在三轴应力状态下的变形、孔隙水压力变化以及强度特性,利用GDS多功能三轴仪,对甘肃引洮输水工程15#隧洞原状黄土进行了常规三轴不排水剪切试验.通过对试验数据的整理与分析发现:在常规三轴不排水剪切试验下,原状Q_2黄土的应力-应变曲线呈应变软化型,表现为脆性破坏;随着围压的增大,曲线的软化性状减弱;在土的峰值强度出现前,变形几乎近似"弹性".土在剪切过程中产生正孔隙水压力,曲线在低围压下具有峰值压力,变化似软化型;在高围压下孔隙水压力随着轴向应变的增加而增大.随着围压的增大,原状Q_2黄土的破坏应力随之提高,有效应力路径曲线形态呈相似的直线形. |
其他语种文摘
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With a GDS multifunctional triaxial apparatus,the conventional consolidated undrained triaxial shear tests were carried out to study the effects of deformation,changes of pore-water pressure and properties of strength of saturated undisturbed Q_2 loess in the fifteenth tunnel of Yintao water transmission project in Gansu province.Based on scientific interpretation and analysis of test data,the stress-strain curve of saturated undisturbed Q_2 loess under a conventional consolidated undrained triaxial shear test showed a strain softening, while the failure model displayed brittle failure.The softening behavior of the stress-strain curve had a trend of attenuation with the increase of confining pressure,and the strain before the peak was approximately elastic. During the process of shear test,the pore-water pressure was positive.Under lower confining pressure,the porewater pressure curve had peak value and the shape of pore-water pressure curve looked like softening.While the pore-water pressure under a larger confining pressure increased with an increasing axial strain.It was also shown that the strength of undisturbed Q_2 loess would increase with the confining pressure and the breaking stress of loess would augment with it.The curve of the effective stress path had a similar linear shape. |
来源
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兰州大学学报. 自然科学版
,2012,48(3):23-27,33 【核心库】
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关键词
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土力学
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Q_2黄土
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三轴剪切
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应变软化
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孔隙水压力
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强度
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地址
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兰州大学土木工程与力学学院, 西部灾害与环境力学教育部重点实验室, 兰州, 730000
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语种
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中文 |
文献类型
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研究性论文 |
ISSN
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0455-2059 |
学科
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建筑科学 |
基金
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国家科技支撑计划项目
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文献收藏号
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CSCD:4589858
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