固有和诱发各向异性对击实粘性土强度和变形特性的影响

Effects Of Inherent and Induced Anisotropy on Strength and Deformation Characteristics of Compacted Cohesive Soil

应用内外室压力不等的空心园柱扭剪仪，对击实粘性土进行了固有和诱发各向异性的试验研究。结果表明，击实粘性土具有明显的固有各向异性，它对土的应力应变关系、强度和变形特性都有不可忽视的影响；不同主应力方向的破坏强度最大差别可达３０％。试样的初始含水量和应力水平会影响固有各向异性程度。诱发各向异性可由卸载和主应力方向旋转产生，它对排水剪强度影响不大，但对应力应变关系和变形特性有较大影响。

A systematical experiment on a compacted cohesive soil has been carried out to investigate the effects of inherent and induced aniatropy. In the tests, a Torsional Shear Hollow Cylinder apparatus with different internal and external pressure to the specimen was used. The results show that the behaviors of stress-strain relation, shear strength and deformation of the compacted cohesive soil depend significantly on the principal stress direction. The maximUm difference of failure strength among various principal stress direction is up to 30%. The initial moisture content of the specimen and sires level can influence the degree of inherent anisotropy. The induced anisotropy is developed by unloading or by continuously rotating the principal stress direction. It das not affect the drained shear strength, but influences the behaviors of stress-strain and deformation sighficantly.