成都理工大学学报（自然科学版）Issue(1)：26-33,8.DOI:10.3969/j.issn.1671-9727.2015.01.04
不同粒径风化砂改良膨胀土的特性试验
Experimental study on characteristics of improved expansive soil by mixing different sizes of weathered sands
摘要
Abstract
The soil particle size has a certain influence on the compaction,strength and swell-shrink characteristics of soils.To study the effect of the different particle sizes of weathered sands on the characteristics of the expansive soil and the influence regularity,combined with the experimental research proj ect of improving the expansive soil characteristics by mixing weathered sands of Yichang City,this paper makes the no-load expansion rate test, shrinkage test, direct shear test and compaction test of the expansive soil improved by mixing weathered sands with diameters (d)<0 .5 mm,0 .5 mm≤d<1 mm and 1 mm≤d<2 mm and obtains the compaction,strength and swelling indexes of the different sizes and different sand ratios of the improved expansive soils.The test results show that the incorporation of the weathered sands can effectively suppress the shrinkage characteristics of the expansive soils, improve the compaction characteristics, and increase the strength of expansive soils and that after mixing sands,the optimum water content,no-load expansion rate,line shrinkage,the shrinkage and shrinkage coefficient of the expansive soils decrease,and the maximum dry density and internal friction angle,and the shrinkage limit increase.Under the same sand ratio,the no-load expansion ratio,line shrinkage and shrinkage of the expansive soils decrease with the increase of the grain size and the internal friction angle,cohesion,the maximum dry density and shrinkage limit increase. Under the same grain size, the optimum water content, no-load expansion rate,line shrinkage and shrinkage of the expansive soils decrease with the increase of the incorporation of sands and the shrinkage limit and internal friction angle increase,the cohesion increases first and then decreases with the increase of the sand ratio.When the particle diameter is 0.5 mm≤d<1 mm and 1 mm≤d<2 mm,the cohesive strength reaches the maximum under mixing sand 20%.When the particle diameter is <0.5 mm,the cohesion reaches the maximum under mixing sand 1 0%. The trend of the maximum dry density changes with the change of the weathered sand diameter.When the particle diameter is 1 mm≤d<2 mm,the maximum dry density increases with the increase of the sand ratio.When the particle diameter is 0.5 mm≤d<1 mm,the maximum dry density increases at first and then gradually reduces with the increase of the sand ratio,and when mixing sand 30%,the maximum dry density reaches the maximum.When the particle size is <0.5 mm,the maximum dry density increases first and then decreases with the increase of the sand ratio, and when mixing sand 20%,the maximum dry density reaches the maximum.关键词
膨胀土/风化砂改良/粒径/胀缩特性/击实指标/内摩擦角/黏聚力Key words
expansive soil/weathered sand/improvement/particle diameter/swelling-shrinkage characteristics/compaction index/internal friction angle/cohesion分类
建筑与水利引用本文复制引用
杨俊,黎新春,张国栋,唐云伟,陈红萍..不同粒径风化砂改良膨胀土的特性试验[J].成都理工大学学报（自然科学版）,2015,(1):26-33,8.基金项目
湖北省教育厅自然科学研究重点项目（D20131304）。 （）
