中文摘要：

以黄石地区软土为研究对象,在不同排水条件、固结压力作用下开展固结蠕变试验,对原状样与蠕变后试样进行扫描电镜观测,分析软土的固结蠕变特性及其微观机制。结果表明：不排水条件下蠕变特性表现更为显著。低偏应力作用下,排水条件下试样的变形大于不排水条件下的变形;高偏应力作用下,则与之相反。排水条件下,变形是由蠕变和固结共同产生的,具有线性蠕变特性;不排水条件下,蠕变是变形的主要原因,具有非线性蠕变特性。蠕变过程中,颗粒间以边-边、边-面为主的接触形式向以面-面为主的接触形式过渡,颗粒间距减小,大孔隙减少,小孔隙增多。固结过程中的主要是自由水以及渗透吸收结合水转化为自由水的排出,而蠕变阶段主要受结合水控制,随着压力加大,孔隙体积减小,结合水膜变薄,增大了土的黏滞性,在长时期就表现为蠕变特性。在软土地基加固过程中可提高土体的排水性能,增大土体的固结程度,降低蠕变带来的危害,提高建筑物的稳定性。

英文摘要：

In order to analyze micromechanism and coupled behaviors of consolidation and creep of soft clay,the consolidation and creep test at different drainage conditions and different consolidation pressures and the scanning electron microscopy test of the undisturbed sample and sample after creep are carried out from soft clay in the Yellowstone region.The results show that the creep behaviors under undrained condition are even more significant compared with under drained condition.Under lower bias stress condition,the deformation under drained condition is larger comparatively and with the opposite conclusion under higher bias stress condition.The deformations under drained condition are induced by consolidation and creep which have linear creep properties;and the deformations under undrained condition are induced mainly by creep which has nonlinear creep properties.The particle distances and large pores are reducing and small pores are increasing with the transition from side-side,side-surface to surface-surface of particles contact form during creep process.The bound water with the form of penetration absorption is changed mainly into free water to excrete during consolidation process and the creep process is mainly controlled by bound water.With increasing pressure and decreasing pore volume,the hydrated film is thin to increase the viscosity of soil which takes on the behavior of creep in the long term.The drainage performance in soft-soil reinforcement can be improved to increase the consolidation degree of soil which can reduce the harms brought by creeping and improve the stability of building.