【摘要】 黄泛区粉质土分布范围广，工程性质较差，作为地基填料时难以压实，在动荷载、雨水浸泡作用下容易诱发湿陷、边坡滑塌、地基土洞等工程灾害，给沿黄区域的工程建设带来不利影响。为深入研究黄泛区粉质土的工程性质，探讨黏粒含量对粉质土工程性质的影响规律，以郑州地区黄河冲积粉土为基本土，通过掺入高岭石、蒙脱石等黏土矿物，配制了不同塑性指数的人工粉质土样本。利用扫描电子显微镜（SEM）对人工配制土的微观结构进行了系统观察，并通过室内试验探讨了其压实特性、崩解性及抗冲蚀性能与塑性指数之间的变化关系。结果表明：掺加高岭石后，镶嵌结构的高岭石团聚体填充粉粒间孔隙，人工配制土的塑性指数降低；掺加蒙脱石后，片状的蒙脱石填充在粉粒间的孔隙中，人工土的塑性指数提高；随着人工配制粉质土塑性指数的增大，其最大干密度呈先显著增大后缓慢减小的趋势，最优含水量则呈先显著减小后缓慢增大的趋势；人工配制粉质土的抗冲系数基本随着塑性指数的增大而增大，两者具有较好的相关性；人工配制粉质土的平均崩解速率随塑性指数的增大基本呈线性递减趋势。此外，塑性指数小于10时，在崩解全过程中人工配制土的崩解速率基本保持稳定；而塑性指数大于10时，人工配制土的崩解可分成起始缓慢崩解和稳定崩解两个阶段；蒙脱石掺量较大时，起始阶段崩解率甚至出现负值。更多还原

【Abstract】 The silty soil in the Yellow River Floodplain has a wide distribution range and poor engineering properties,which is difficult to compact when used as foundation fill material. Further, the silty soil foundation is prone to induce engineering hazards such as collapsibility, slope failure, and the formation of cavities in foundation soils under action of dynamic loads and rainwater infiltration, which adversely affects the construction of projects in the Yellow River region.In order to further study the engineering properties of silty soil in the Yellow River Floodplain and investigate the effect of clay content on the engineering properties of silty soil, the Yellow River alluvial silty soil in Zhengzhou city was used as the basic soil, and artificial silty soil with different plasticity indices was prepared by adding kaolinite, montmorillonite in different proportions. The microstructure of the artificially prepared soil was systematically examined using scanning electron microscopy(SEM), and the relationships of its compaction characteristics, disintegrability, and scour resistance with the plasticity index were investigated through laboratory tests. The results indicate that after adding kaolinite, the mosaic-structured kaolinite aggregates fill the pores between silt particles, leading to a decrease in the plasticity index of the artificially prepared soil. After adding montmorillonite, the flaky montmorillonite fills the pores between silt particles,resulting in an increase in the plasticity index of the artificial soil. As the plasticity index of the artificially prepared silty soil increases, its maximum dry density first increases significantly and then slowly decreases, while its optimal water content first decreases significantly and then slowly increases. The scour resistance coefficient of the artificially prepared silty soil generally increases with the increase of plasticity index, and the two have a good correlation. The average disintegration rate of the artificially prepared silty soil generally decreases approximately linearly with an increase in the plasticity index. In addition, when the plasticity index is less than 10, the disintegration rate remains basically stable throughout the entire process. When the plasticity index is greater than 10, the disintegration process can be divided into two stages: an initial slow disintegration stage and a stable disintegration stage. When the amount of montmorillonite is large, the initial disintegration rate may even become negative.更多还原