高应力下重塑黄土蠕变特性试验

Test on Creep Characteristics of Remolded Loess Under High Stress

以延安地区黄土高填方填筑体为研究对象,进行了控制含水率和压实度的高压固结蠕变试验。分析了初始含水率、压实度、固结压力等因素对重塑黄土蠕变特性的影响。使用对数函数对试验结果进行拟合,得到了适合描述延安地区黄土高填方填筑体工后沉降的蠕变模型。试验结果表明:减小初始含水率或增大压实度,能在一定程度上降低土体的蠕变量,从而更好地控制高填方工程的工后沉降。固结压力越大,试样达到稳定所需的时间越长,最大固结压力(2 400 kPa)时,蠕变稳定时间是低固结压力(100 kPa)时蠕变稳定时间的4倍左右。该本构模型能够较好地反映出延安地区黄土高填方填筑体的蠕变特性。

The high loess-filled embankment in Yan'an area was taken as research object. The high pressure consolidation creep tests were carried out under the control of moisture content and compaction degree. Theeffects of initial moisture content,compaction degree and consolidation pressure on the creep characteristics of the remolded loess were studied. A creep model that suitable for describing the post-construction settlement of high loess-filled embankment in Yan'an area was obtained by using logarithmic function fitting. The results show that the creep of soil is reduced by decreasing initial moisture content or increasing compaction degree,so the post-construction settlement of high loess-filled embankment is controlled better. With the increase of consolidation pressure,the samples need more time to reach stability. Under the condition of maximum consolidation pressure( 2 400 kPa),the stability time of creep is about 4 times as much as that under the low consolidation pressure( 100 kPa). The creep characteristics of high loess-filled embankment in Yan'an area can be reflected better by the constitutive model.