人工制备结构性软黏土长期变形特性试验研究

软黏土的结构性对其变形特性有很大的影响，由于成因等因素的不同，软黏土的结构性强弱不一，这也使得土体变形特性表现出差异性。为研究结构性强弱不同对软黏土长期变形特性的影响，人工制备含水率相同而结构强度不同的软黏土，对其进行三轴不固结不排水蠕变试验，研究结构性对软土长期变形特性的影响。试验结果分析表明，具有一定结构性的软黏土，当偏应力小于结构屈服应力时，土体结构损伤少，其蠕变变形量较小，一般不大于2%；而随着偏应力的增大，尤其是超过结构屈服应力时，土体结构出现大量破坏，应变增长很快，最终演变为临界型应变。相同偏应力作用下，土体结构性越强，各时刻的蠕变变形量也越小。在此基础上，以土体结构强度作为表征土体结构性强弱的量化参数，建立了考虑结构强度影响的长期变形预测公式。

An experimental study of the long-term deformation characteristics of artificial structured soft clay

The structure of soft clay has a great effect on its deformation characteristics, and it shows difference in strength as affected by such factors as origins, which also leads to some differences in the soil deformation characteristics. In order to examine the effect of structural strength on the long-term deformation characteristics of soft clay, creep tests under unconsolidated-undrained conditions were conducted for artificial soil with the same moisture content and different structural strengths. The results show that for soft clay with certain structure, when the deviatoric stress is less than the structural yielding stress, the soil structure has a small yield failure, and its creep deformation is small, generally less than 2%. With the increasing deviatoric stress, the soil structure appears lots of structural failure, especially when the structural yield stress is exceeded, and the strain develops quickly, eventually evolves into a critical strain. Under the same deviatoric stress, the stronger the soil structure, the smaller the creep deformation at any time. The soil structural strength is taken as a quantitative parameter, which represents the level of the soil structure and is used to establish a long-term deformation prediction model considering the influences of structure.