搜集汇总黄河口埕岛海域地质勘察资料,研究该区土性参数区域分布特征,包括分析海域内土体类别,绘制不同区域内地基承载力、标贯击数、粘粒含量、含水量、孔隙比和液塑限等值线图。研究发现,海域表层土体主要由粉土和粉质粘土组成,此外还有小面积的粉砂和淤泥质土,中部大面积地区为粉土,东南区域分布有粉质粘土和淤泥质土;地基承载力较高的区域主要分布在海域中部与西南部,海域的北部与东南部土体强度较低,并且含水量、孔隙比和液塑限也较大,土性区域变化与水深变化特性较为一致。最后分析土性区域变化机理认为,极端海况下该区土体发生液化剪切破坏,沿斜坡滑移运动一定距离后再次沉积可形成这种现象。
On the basis of collection, summarization and analysis of geological data obtained during previous surveys, the regional variations of soil properties of the surface sediments in the Chengdao sea area of the Huanghe Esturary are studied, which include soil type, foundation bearing capacity, SPT-N, clay particle content, water content, void ratio and liquid and plastic limits. The results indicate that the surface soils in the study area are mainly composed of silt and silty clay, with a small area of silty sand and muddy soil being present. In the central part of the study area a large area of silty soil is distributed and in the south- eastern part silty clay and muddy soil are dominated. The foundation bearing capacity is higher mainly in the central and southwestern parts of the study area, whereas in the north and the southeast the soils are relatively lower in strength and higher in water content, void ratio and liquid and plastic limits. The regional variations of soil property are basically in agreement with the changes of water depth. The mechanism of the regional variations of the soil property is analyzed and considered to be mainly due to the liquifaction and shearing of soil bodies occurring at extreme sea conditions and the redeposition after the soils sliding along a slope for a certain distance.