非饱和黏性土的抗拉强度与抗剪强度关系试验研究

 通过对具有一定抗拉强度的非饱和黏性土在不同含水量状态下的重塑土样进行剪切和拉伸对比试验研究，结果表明，非饱和黏性土的抗剪强度指标c和j在一定范围内都随含水量的增大而减小；以三轴拉伸试验围压为大主应力、轴向应力为小主应力所确定的各应力圆符合莫尔–库仑准则；物理性状相同的非饱和黏性土重塑土样的抗拉强度与抗剪强度存在一定的函数关系。提出在无拉伸试验条件情况下，可通过相应物理性状的剪切试验结果计算非饱和黏性土的抗拉强度思想。

EXPERIMENTAL STUDY ON RELATIONSHIP BETWEEN TENSILE AND SHEAR STRENGTH OF UNSATURATION CLAY EARTH MATERIAL

In order to find out the qualitative and quantitative relationships between triaxial tensile strength and triaxial shear strength，contrast experiments are carried out including triaxial tensile，triaxial shear and uniaxial tensile with remolded samples of unsaturated clay in core wall of Heihe Dam in Xi¢an，Shannxi province under different moisture contents. The experimental results show that：(1) the shear intensity index of unsaturated clay c and j decrease with the increasing of moisture contents；(2) though triaxial or uniaxial experiments of unsaturated clay，the Mohr circle，which is decided by confining pressure as major principal stress and axial stress as minor principal stress，accords with Coulomb criterion；and (3) there is functional relationship between tensile strength and shear strength of different unsaturated clay samples with same physical nature. Based on these conclusions，tensile strength of unsaturated clay can be estimated through results of shear tests without tensile strength test conditions.