Correlation analysis of physical and mechanical parameters of inland fluvial-lacustrine soft soil based on different survey techniques

Abstract Based on the collected soil property index test data of more than 2,500 groups of inland fluvial-lacustrine soft soil, the correlation of physical and mechanical parameters of this soft soil was systematically analyzed. The results show that the physical indexes of inland fluvial-lacustrine soft soil are close to that of marine soft soil, while its mechanical indexes are higher. However, the variation coefficient of its mechanical indexes is much larger than that of the physical indexes. In addition, it is found that the cone penetration parameters of this soft soil are significantly correlated with its physical and mechanical indexes by establishing a series of empirical relationships between the static point resistance and the natural unit weight, the liquidity index, the quick shear cohesion, and vane shear strength. On the basis of the previous research results, the disturbance strength of inland fluvial-lacustrine soft soil can be converted into in situ strength by deriving the theoretical formula between the vane shear strength and the disturbance degree. The calculation process of the above conversion relation is explained in detail through an engineering case, which indicates that the theoretical formulas have good applicability for inland fluvial-lacustrine soft soil.