姜洪伟    （中环投资开发（集团）有限公司 上海 200063）

     张鹏飞  赵锡宏       （同济大学 上海 200092）

[提要]  将土的各向异性不排水剪强度应用到滑移线场理论中，得出不等向固结（K₀固结）粘土地基极限承载力系数的理论解。对不同试验条件下的极限承载力系数及其与K₀或 φ‘（有效内摩擦角）的关系进行分析，得到一些有益的结果。通过模型试验的计算结果与实测值的比较，证明本文理论的合理性和有效性。理论分析及计算结果表明，对于K₀固结粘土，实践中通常使用的极限承载力系数N_cu=5.14，如不经修正是不适宜的。最后通过现场载荷试验和工程实例对本文方法和常规各向同性方法进行了比较分析。
[关键词]  各向异性 承载力系数 不排水剪强度 K₀固结 极限平衡

By applying the anisotropic undrained shear strength in the theory of slip lines field, the bearing capacity of strip footings placed on the anisotropically consolidated clays may be evaluated. The bearing capacity factors for various shear tests connecting with K₀-value and effective internal friction angle are theoritically analysed and some useful results are obtained. Through comparison between the calculated and measured results from model tests, the validity of present theory is verified. After theoritically analysed, the result shows that for K₀-consolidated clay,  the isotropic bearing capacity factor( N_cu= 5.14) conventionally used in practice can not be continually used without any correction. Finally, the present method is compared with the conventional method through field test and practical engineering.
Keywords: anisotropy; bearing capacity factor; undrained shear strength; Ko-consolidation