湛江强结构性黏土的三轴排水蠕变特征

 利用GDS应力路径三轴试验系统，开展不同围压下湛江强结构性黏土的三轴固结排水剪切蠕变试验，获得其轴向应变、体应变与应力和时间的关系，分析蠕变性状的结构性效应，建立相应的蠕变模型。结果表明，湛江黏土的蠕变变形演化特征受其强结构性制约，其蠕变特性的敏感程度与结构性强弱相关联。在低偏应力下，其蠕变变形和变形速率均较小；偏应力超过临界值后，土体在短时间内发生破坏。湛江黏土在?3＜?k时，其体变性状总体上表现为剪缩，但随时间变化出现一定的剪缩和剪胀交替性，即存在回弹现象；而当?3≥?k时，则表现为剪缩。蠕变引起的强度衰减主要表现为黏聚力的降低，且 77.63%。采用6元件扩展Burgers模型能较好地描述湛江黏土的瞬时弹性应变、衰减蠕变和稳定蠕变3个阶段。在实际工程中，必须对土的结构性给予充分的认识，在较低应力范围内，可以利用其结构性的有利因素，但设计荷载严禁超出结构屈服应力。

CREEP BEHAVIOR OF ZHANJIANG STRONG STRUCTURED CLAY BY DRAINED TRIAXIAL TEST

The drained triaxial shear creep tests for Zhanjiang strong structured clay under different confining pressures by GDS triaxial testing system are performed. The relationships of axial strain and volumetric strain with stress and time are obtained. The effect of soil structural property on its creep behavior is analyzed;and the corresponding creep model is established. The results show that the evolution characteristics of creep deformation of Zhanjiang clay are restricted by its poorly structural property;...