非饱和黏土有效应力强度指标计算

因非饱和土性质的复杂性，需用高精的设备获取相关强度参数，试验难度大，应用受到限制。在分析非饱和土强度理论的基础上，从土的有效应力强度出发，利用常规三轴仪开展不同含水率、干密度组合的黏土CD试验，探讨含水率及干密度对黏土抗剪强度的影响，据此建立考虑含水率（饱和度）、干密度影响的有效应力强度指标计算公式。研究表明，黏土的强度与含水率、干密度密切相关，其中黏聚力、内摩擦角均与含水率（饱和度）呈二次曲线关系，与干密度成线性关系；二者的交互影响可按乘法效应进行组合，研究成果可为工程应用提供参考。

Calculation of effective strength indexes of unsaturated low liquid limit clay

Because of complexity about property of unsaturated soil, getting correlative strength parameters needed high and extract equipment, the difficulty is big so that its application is limited. Based on an analysis of strength theory of unsaturated soil, CD test of clay about different combination of water content and dry density is carried out with normal three-axis test. According to the theory of effective strength of soil, the effective strength of clay about water content and dry density is discussed, thus functions of total strength indexes are established that the effect of water content(saturation) and dry density can be considered. Study shows that strength of clay has close connection with water content and dry density. Moreover, the relation between cohesion, internal friction angle and water content(saturation) is conic, the relation between cohesion and dry density is linear, and the mutual effect of the both can be expressed by multiplication. Our research can be used as a reference application of project.