黄土微观参数指标与动弹性模量关联度研究

取岷县地震台、庆阳黄土塬2～12m深度土层的粉土、粉质黏土样品,通过室内动三轴和扫描电镜试验,测定了动弹性模量和微观结构特征,研究了粉土、粉质黏土的动本构关系,并采用关联度分析法研究了黄土竖向(沉积向)和横向(垂直于沉积向)的微观结构与最大动弹性模量之间的关系。研究结果表明:粉土和粉质黏土的动本构关系都符合Hardin-Dinevich双曲线模型。分形维数、概率熵和平均形状系数的变化对粉土、粉质黏土的最大动弹性模量的影响最敏感。其次是平均周长、长轴、短轴,而平均面积对其影响则相对较小。针对粉土横竖向关联度,横向微观参数对最大动弹性模量的影响更敏感;而粉质黏土,竖向微观参数对最大动弹性模量的影响更敏感。

Correlation between microscopic parameters and dynamic elastic modulus of loess

The silty soil and silty clay samples of 2~12 m-deep soil layer of the Minxian Seismic Station and the Qingyang Loess Plateau are studied by the dynamic triaxial and scanning electron microscopy experiments, and the dynamic elastic modulus and microstructure characteristics are measured. The dynamic constitutive relation of silty clay is studied. The relationship between the vertical structure of the loess and the transverse (perpendicular to sedimentary direction) and the maximum dynamic elastic modulus are studied by the correlation analysis method. The results show that the dynamic constitutive relations of silt and silty clay are consistent with the Hardin-Dinevich hyperbolic model. The influences of fractal dimension, probability entropy and average shape coefficient on the maximum dynamic elastic modulus of silt and silty clay are the most sensitive. Secondly, for the average circumference, long axis and short axis, the average area has a relatively small impact on them. In view of the vertical and horizontal correlations of silt, the influences of transverse microscopic parameters on the maximum dynamic elastic modulus are more sensitive. For the silty clay, the influences of vertical microscopic parameters on the maximum dynamic elastic modulus are more sensitive.