中文摘要：

对部分应用土-水特征曲线来预测非饱和土抗剪强度的公式进行了归纳分析。应用压力板仪与非饱和三轴仪，测试了荆门原状弱膨胀土的土-水特征曲线和控制吸力的非饱和三轴抗剪强度参数，并将试验结果与各抗剪强度公式的预测值进行对比，分析了各强度公式的局限性。试验结果表明，非饱和原状膨胀土的净法向应力摩擦角随着吸力的不同而变化，根据双应力变量理论确定的吸力对强度的贡献与围压有关，不同围压下吸力对强度的贡献不同，表观凝聚力气τvs与吸力间符合乘幂函数关系。

英文摘要：

Several formulas for predicting the shear strength of unsaturated soils by the soil-water characteristic curve （SWCC） are summarized and discussed. The SWCC and unsaturated shear strength parameters of intact weak expansive soil from Jingmen City, Hubei Province are measured by the pressure plate and unsaturated triaxial apparatus; based on the comparison of the test results with the predictive values of the several shear strength formulas, the limitations of the formulas are analyzed. The results show that the friction angle of the net normal stress varies with the change of matrix suction for the unsaturated intact expansive soil. According to the double stress variables theory, the contribution of matrix suction to the shear strength of unsaturated expansive soil is associated with cell pressure and different in different cell pressure levels; it is suitable that the variable characteristic of the apparent cohesion τvs with suction is described by power function.