考虑结构性与排水条件的吹填软土的流变特性

Rheological characteristics considering structure and drainage condition of the soft dredger fill

软土普遍具有结构性与流变特性。以天津滨海新区吹填场地有一定结构性的吹填软土为研究对象,通过三轴流变试验仪,开展了排水条件以及结构性对其流变特性影响的研究。试验结果表明,排水条件对流变有明显影响。不排水时,流变变形大;排水时,虽然总变形量大,但固结变形占较大比例,流变变形比例小,实际工程实践中可通过增加土体的排水条件减少流变的影响。结构性对土体流变的影响主要体现在所受外部荷载与结构屈服应力大小之间的关系。当外荷载小于结构屈服应力时,流变变形小;当外荷载大于结构屈服应力时,伴随着土结构的破坏,流变变形明显增大,但还是小于同条件下无结构性的重塑土。

Soft soil has structural and rheological characteristics usually.Through three triaxial rheological test,the paper studied the rheological properties effected by drainage conditions and structure on the basis of structural soft dredger fill in Tianjin Binhai new area.The results showed that the drainage conditions do have an obvious effect on rheological characteristics.Under conditions without drainage,rheological deformation is obvious;on the contrary,although the total amount of deformation is huge,rheological deformation has a small proportion,so we can reduce the rheological effect by improving the drainage conditions of soil in engineering practice.Effect of structure on rheology mainly reflected the relationship between the external load and the structure yield stress.When the external load is less than the yield stress,the rheological deformation is small;on the contrary situation,rheological deformation will increase significantly accompanied by the damage of soil structure,but it is still smaller than unstructured remodeling soil under the same conditions.