基于双曲线临界状态的改进剑桥模型及数值实现

针对传统剑桥模型不能很好反映重塑黏土力学及临界强度特性的缺陷，在试验研究的基础上，对其临界状态进行改进。不排水三轴试验发现，重塑黏土的临界状态线表现为双曲线的形态，因此，将双曲线临界状态与剑桥模型相结合，建立改进的剑桥模型，并在FLAC3D程序中进行二次开发。同时针对FLAC3D中对塑性因子算法较为繁琐的问题，引入牛顿–辛普森迭代法进行改进。最后，运用改进的剑桥模型对不同压实度土样进行三轴数值模拟试验。结果表明：改进的剑桥模型能较好地反映重塑土体的力学特性，改进后的算法计算精度较高，执行效率较好。

IMPROVED CAM-CLAY MODEL BASED ON HYPERBOLIC CRITICAL STATE AND ITS NUMERICAL IMPLEMENTATION

Aiming at the defects that the Cam-clay model cannot reflect the mechanics and strength characteristics of the remolded clay，based on the test research，the critical state line is improved. Through the undrained triaxial test，it is found that the critical state line of the remolded unsaturated clay has a shape of hyperbola. Therefore，the improved Cam-clay model is established based on the combination of hyperbolic critical state and the traditional Cam-clay model，and its secondary development is carried out in FLAC3D program. At the same time，Newton-Simpson iterative method is used to improve the relatively complex algorithm for plastic factor in FLAC3D. Finally，three axis numerical simulation tests on soil samples with different compactness are carried out using the improved Cam-clay model. The results show that，the mechanics characteristics of remolded unsaturated soil can be well reflected by the improved Cam-clay model；and the improved algorithm has higher precision and better performance.