针对研究区(黑方台地区)黄土的非饱和蠕变特性,采用改进型的FSR-10非饱和三轴蠕变仪进行了基质吸力控制条件下的三轴蠕变试验,研究发现:(1)当施加的偏应力较小时,黄土的变形较小,并具有一定程度的可恢复性,随着偏应力的增加,土颗粒需经过较长的时间才能够移动到新的位置,达到新的平衡,当偏应力增加到一定程度时,颗粒移动难以达到平衡,土样发生破坏。(2)在其他条件相同的情况下,围压与试样产生的变形量呈负相关,且围压越小,变形达到稳定所需的时间也越长;(3)在围压和偏应力水平一定的情况下,土体的变形量随基质吸力呈负相关,且基质吸力越小,蠕变曲线达到稳定所需的时间越长。
For the unsaturated loess, the improved FSR-10 unsaturated triaxial creep testing apparatus is used to perform the triaxial creep test under the condition of the matric suction control. The resuhs indicate that less applied deviatoric stress results in less deformation of the loess, and such deformation is recoverable to some extent. As the deviatoric stress increases, it takes a longer time for soil particles to move to a new position and reach a new balance. When the deviatoric stress increases to a certain degree, it is hard for the particles to move to a balanced state, and the soil sample is damaged. When other conditions are the same, the confining pressure is inversely correlated to the sample deformation, and smaller confining pressure results in a longer time needed for stabilizing the deformation. When the confining pressure and the deviatoric stress are fixed, the deformation of soil is inversely correlated to the matric suction, and smaller matric suction results in a longer time needed for stabilizing the creep curve.