原状黄土基于动扭剪试验的动力特性研究  

Study on Dynamic Properties of Undisturbed Loess Under Dynamic Torsional Shear Test

作　　者：尚宏世 

机构地区：[1]兰州理工大学理学院,甘肃兰州730050

出　　处：《科技创新与生产力》2016年第3期105-107,110,共4页Sci-tech Innovation and Productivity

摘　　要：通过动静扭剪三轴仪对兰州原状黄土的动应力应变曲线及本构关系、动剪切模量和动阻尼比变化特性进行研究。结果表明,3种类型黄土的动应力应变关系呈双曲线型;3种黄土在不同的固结应力作用下,动剪切模量都随动应变的增加而减小,且减小的幅度越来越小;在固结应力作用相同的情况下,最大动剪切模量大小依次为：干型黄土〉湿型黄土〉饱和黄土;固结应力比相等时,围压越大,3种黄土的最大动剪切模量也越大;原状黄土的阻尼比一般在0.2~0.3之间且阻尼比λ与动剪应变对数lg（γd）具有线性相关性。Lanzhou undisturbed loess is divided into dry pattern, wet pattern and saturated pattern according to original water content. The three patterns are studied by using torsional shear apparatus. The constitutive relationship between dynamic stress and dynamic strain, the dynamic shear modulus, and the dynamic properties of the damping ratio are studied. The study indicates that the curve for dynamic stress and dynamic strain of the three patterns is a hyperbolic curve. The dynamic shear modulus of the three patterns under the different consolidation will be decreasing with the increase of dynamic strain, and the size will be smaller. Under the same consolidation, the order of maximum dynamic shear modulus is that, dry patternwet patternsaturated pattern, the damping ratio of undisturbed loess is generally between 0.2 to 0.3, and the relationship between damping ratio and dynamic strain is linear.

关 键 词：原状黄土 动力特性 动扭剪试验 动应力应变关系 动剪切模量 动阻尼比 

分 类 号：P642.131[天文地球—工程地质学]