非饱和黏土动力特性及等价黏弹性模型的试验研究

针对非饱和重塑黏土，利用改进的非饱和土静力-动力液压三轴-扭转多功能剪切仪，在固结排水（CD）条件下进行了应力控制式分级加载的循环三轴试验，通过对试验结果的对比分析，探讨了初始固结压力和基质吸力(孔隙气压力Ua与孔隙水压力Uw之差)对非饱和土动应力-动应变关系特性的影响。以此为基础，将Hardin-Drnerich等价黏弹性模型和Masing加卸载准则进行了改进，并得到了可以考虑基质吸力的非饱和黏土的等价黏弹性模型。进而对试验数据与模型预测结果进行比较，结果表明这种改进的非饱和土等价黏弹性模型能较好预测各种基质吸力下非饱和土的动应力-动应变关系。

Experimental study of dynamic behavior and equivalent viscoelastic model of unsaturated clay

The improved static and dynamic universal triaxial and torsional shear apparatus for unsaturated soil is employed to perform step stress controlled cyclic triaxial tests under consolidated drained condition. Through a series of tests on unsaturated remoulded clay, the effects of initial confining pressure and matric suction (pore air pressure Ua pore water pressure Uw) on stress-strain behavior are examined. The equivalent viscoelastic model of unsaturated clay considering the influence of matric suction is recommended by improving the Hardin-Drnerich equivalent viscoelastic model and Masing loading and unloading criterion of saturated soil. Moreover, it is verified through comparing experimental data and former improved model that the recommended equivalent viscoelastic model of unsaturated clay can be used to predict the stress-strain behavior of unsaturated soil.