(1. Department of Geological Engineering，Qinghai University，Xining，Qinghai 810016，China；2. School of Civil Engineering，Qinghai University，Xining，Qinghai 810016，China；3. State Key Laboratory of Hydroscience and Engineering， Tsinghua University，Beijing 100084，China)
Abstract：In order to study the impacts of anisotropy of compacted loess on strength and deformation behavior，a series tests with fixed principal stress direction were carried out on compacted loess with a hollow cylinder apparatus. The impacts of intermediate principal stress coefficient b and principal stress orientation angle α on strength and deformation of compacted loess were emphatically discussed. Test results revealed that when α increased the strength of compacted loess decreased first and increased when ＞60°. Tangent modulus of generalized shear stress-strain curves of different intermediate principal stress coefficient decrease with principal stress orientation angle increase from 0°to 30°，and increase with principal stress direction when ＞60°. The peak of generalized shear stress was used as the failure criterion of compacted loess according to the generalized shear-strain curves. The generalized shear stress at the generalized shear strain of 15% can be taken as the failure criterion when peak generalized shear stress did not appear. The impact of intermediate principal stress coefficient on strength is mainly manifested in the strength of b = 0.5 are lower than b = 0.0 for different principal stress directions.
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2015, Vol. 34 
