Abstract: Natural sedimentary ground deposited in the north shore of the Yangtze River delta mainly consists of silty and fine sandy soils. The permeability varies within 10-7-10-3 cm/s, less than the order of 10-3 cm/s responsible for completely drained condition but larger than the order of 10-7 cm/s responsible for completely undrained condition. Little study has been carried out on such natural intermediate soils in China. In this study, a series of physical and mechanical tests were performed on both the undisturbed and the remolded samples obtained from three sites in the north shore of the Yangtze River delta along Tongqi highway. The results indicate that the physical properties are similar to natural clayey soils with moderate sensitivity, but the tip resistance obtained by the in-situ cone penetration tests is almost the same as that of stiff clayey soils with liquidity index almost equal to zero. This study also illustrates that the grain size distributions of natural sedimentary intermediate soils have a significant effect on tip resistance. The grey correlation analysis utilized to analyses correlation between physical state index and mechanical character index for this clayey intermediate soils. It is clearly discovered that the void ratio utilized for sandy loam consistency partition and water content ratio for the silty clay and the clay consistency division are much more rational.

Key words: consistency limits, grain size distributions, natural sedimentary intermediate soils, natural water content, permeability, tip resistance, grey correlation analysis