复杂应力下黄土蠕变特性试验研究

为了研究陕西省杨凌示范区黄土边坡的稳定性，采用改进的应力型三轴蠕变仪对所取黄土试样进行了一系列室内三轴固结不排水蠕变试验。试验结果表明：含水率、干密度、偏应力水平对黄土的蠕变特性均有较大的影响，表现为含水率一定，偏应力愈大时，黄土的蠕变变形量较小；偏应力水平一定时，含水率愈大，蠕变现象愈明显，产生的蠕变应变量愈大；其他条件相同时，干密度愈大，黄土试样的蠕变变形愈小。在黄土边坡治理工程中可通过改善边坡排水和增加边坡土体压实情况减小蠕变破坏的可能性。通过对试验数据分析得出了适合杨凌地区黄土的经验蠕变模型，通过与Singh-Mitchell模型和Mesri模型的比较发现，该模型具有精度高、参数少且易获取的优点，并能很好地描述黄土的蠕变特性。

Research on creep characteristics of loess under complex stress

To investigate the stability of loess slope in Yangling district of Shaanxi province, a series of laboratory undrained triaxial creep tests of loess specimens taken from a slope are performed by stress triaxial creepmeter. The test results indicate that the creep characteristics of loess are obviously influenced by water content, dry density and consolidation pressure. When the water content is invariable, the creep strain reduces with the increase of consolidation; when consolidation pressure is invariable, creep phenomenon is significant with higher water content and the creep strain becomes bigger; as dry density increases, the creep deformation of soil specimen becomes smaller. In the treatment of loess slope, enhancing the drainage ability of loess slope and increasing the compactness of soil can reduce the probability of creep rupture. According to the analysis of experimental data, a new empirical creep model is proposed; it shows a significant advantage of better applicability, higher accuracy and fewer parameters in simulating the creep characteristics of loess in Yangling district after the comparison with Singh-Mitchell and Mesri models.