Secondly , true taixial test by load in three different principal stress direction for study on soil anisotropic deformation characteristic are processed . lateral deformation relative to load direction , lateral deformation relative to lateral direction and the stess - strain relationship in load direction are analyzed , and soil anisotropic deformation characteristic on the three aspects of elastic ratio , poisson " s ratio and the property of compliment matrix are completely analyzed too 其次,为揭示土体各向异性变形特性,有针对性进行了三主应力分别单向加荷的真三轴试验研究,分析相对于加荷向的侧向变形、互为侧向的侧向变形、不同主应力加荷向的应力应变关系各向异性性状。